The Africa Cup of Nations is in full swing following its big kick-off on Sunday, and Monday sees the action taken up a notch.

There will be twice as many games as Group B and Group C get under way, providing first opportunities to see two of the pre-tournament favourites: Morocco and Senegal.

But the shroud of COVID-19 lingers over practically every AFCON match at the moment, and it will be especially difficult to ignore its impact on games on Monday, with the likes of Senegal, Guinea, Malawi and Gabon all missing key players.

Senegal v Zimbabwe (13:00 GMT)

Senegal's second so-called 'golden generation' is running out of time.

They arrived in Cameroon with a stacked squad, but many of their key players are approaching 30 or are already there.

To make matters worse, coach Aliou Cisse is without a host of big players against Zimbabwe, a game he will be keen to just get out of the way.

"I was looking at the composition of our team," Cisse said. "Compared to our last match against Congo, I can already tell you we have six indisputable starting players who are not on the squad list: Edouard Mendy, Krepin Diatta, Ismaila Sarr, Nampalys Mendy, Kalidou Koulibaly and Saliou Ciss.

"Having six absent starting players, it's true that it's worrying."

One to watch: Sadio Mane (Senegal)

Senegal have one of the best squads – if not the very best – in the tournament, but they are going to rely on Mane to a certain degree, particularly given their COVID-19 absences. Thankfully he is exceptional both when it comes to sniffing out chances and creating them, with his 0.67 non-penalty expected goal involvements every 90 minutes being the fourth-best in the Premier League (min. 900 minutes played) this term.

Guinea v Malawi (16:00 GMT)

Both Guinea and Malawi have been among the sides struck by coronavirus ahead of this tournament, but the former should still fancy their chances on Monday against a team considered Group B's rank outsiders.

Anything but three points will be a major disappointment for Guinea on matchday one, and key player Naby Keita is not among those to be afflicted with COVID-19.

As such, coach Kaba Diawara is feeling confident.

"We have the ambition to go as far as possible in this competition, which is why I accepted this mission," Diawara told Africa Top Sports ahead of the tournament.

"It's clear that it is the results that will speak. We try to put things in place, sometimes it works, sometimes it doesn't."

One to watch: Mohamed Bayo (Guinea)

While Naby Keita may be the team's most-recognisable star, expectations on Bayo are significant given he heads into the tournament with nine Ligue 1 goals to his name with Clermont this season, 45 per cent of their total output, and only one was a penalty. Only Jonathan David (12) and Wissam Ben Yedder and Ludovic Ajorque (both 10) have scored more in the French top flight so far.

Morocco v Ghana (16:00 GMT)

After Senegal (60.9 per cent), Morocco are the likeliest to finish top of a group at the AFCON (52.6 per cent), according to Stats Perform analysis. This speaks to the quality in the side assembled by Vahid Halilhodzic.

Even without Chelsea star Hakim Ziyech, who has been exiled, Morocco boast some fine players and will be expected to go deep into the competition – not that coach Halilhodzic is taking anything for granted.

"We have to prepare well to face the three teams in the group: Ghana, Gabon, and the Comoros," the Bosnian told reporters.

"Although Morocco are favourites to reach the second round, we have to prepare well and play with a lot of ambition and determination to go as far as possible."

One to watch: Yassine Bounou (Morocco)

This is likely to be Morocco's biggest challenge in the group stage, so they will want to be solid at the back. Bounou should help them in that respect – the Sevilla goalkeeper's 25 clean sheets in all competitions in 2021 was a total bettered only by Ederson (26) and Edouard Mendy (27) across the top five leagues in Europe.

Comoros v Gabon (19:00 GMT)

Comoros' Group C opener will be a momentous game as they play in a major international tournament for the first time.

Making a splash will be tough, but coach Amir Abdou is adamant they are more than worthy of their place in Cameroon.

He told Africa Foot United: "We haven't qualified by chance. We therefore don't think that we will let the opportunity to go as far as possible slip away.

"We will fight with our weapons with our various opponents, as tough as they are."

One to watch: Denis Bouanga (Gabon)

Gabon are likely to be without two of their most experienced players in Pierre-Emerick Aubameyang and Mario Lemina due to coronavirus, meaning others will need to step up. Bouanga will probably be among those expected to take on greater responsibility. The gifted Saint-Etienne left-winger is a good dribbler and takes a lot of shots, his 3.4 attempts per 90 minutes being the fifth-most in Ligue 1 this season (min. 900 minutes played).

Liverpool are not worried about being without Mohamed Salah, Sadio Mane and Naby Keita while they are on Africa Cup of Nations duty, according to assistant Pep Lijnders.

The trio all played in Sunday's thrilling 2-2 Premier League draw with Chelsea in their final outing before linking up with their respective national sides.

Mane and Salah were both on target at Stamford Bridge as Liverpool raced into a two-goal lead, while Keita was introduced in the second half after Chelsea had levelled up through Mateo Kovacic and Christian Pulisic.

Key attacking pair Salah and Mane have played in 26 of Liverpool's 29 matches this term – the joint-most of any Reds players, with Jordan Henderson (25) next on the list.

Between them, they have scored 33 of their side's 77 goals in 2021-22, while chipping in with a combined 10 assists.

Liverpool could now potentially be without both players, as well as midfielder Keita, until the second week of February depending on how far their countries advance at the Africa Cup of Nations.

But Lijnders, who filled in for Jurgen Klopp against Chelsea after the German tested positive for coronavirus, is confident others in the squad can now step up.

"You can try to plan it, but you can never prepare it," he said.

"It is not a worry because we have faith in the boys we have and a few boys are coming back as well.

"We know that certain players can play more offensively as well, they have been playing in midfield, but they can play more offensively as well."

Salah and Mane will link up with Egypt and Senegal respectively, while Keita is part of Guinea's squad for the tournament in Cameroon.

Losing three regulars during a hectic period in the season and with others out through coronavirus and injury is not ideal for Liverpool, but Lijnders has wished the trio well.

"I just told the boys that they should try to win the AFCON because it is a prize to catch and the careers are never long and they deserve to fight for each prize," Lijnders said.

"This prize now comes in front of them – it’s a tournament with so much passion, so much culture and it is a really proud situation if you can play for your country.

"If it's England or Germany or Holland or whoever, that's what they have and feel.

"So they are African legends, they are legends for me, but if they win it they will probably be even bigger legends so they should try with all they have to win it."

Roberto Firmino missed the Chelsea game after contracting COVID-19, while Takumi Minamino and Divock Origi are currently nursing injuries.

Asked when those players are expected to return to training, Lijnders said: "Let's see. 

"Some of the boys plan to be back, but they still didn't start team training, so we have to see."

Lijnders confirmed Klopp will still be absent for the first leg of Liverpool's EFL Cup semi-final tie with Arsenal on Thursday as he continues to self-isolate.

Senegal have accused Watford of blocking Ismaila Sarr from linking up with the national team ahead of the upcoming Africa Cup of Nations.

Sarr has not played for Watford since November 20 due to a knee ligament injury and is not expected to return to fitness until the end of this month at the earliest.

Despite still being out injured, Senegal named the 23-year-old in their squad for the tournament, which runs from January 9 until February 6.

However, Watford informed Senegal earlier this week that Sarr will not be allowed to travel.

It is the second Africa Cup of Nations row Watford have been embroiled in after Nigeria accused the Premier League side of "baring fangs" after objecting to Emmanuel Dennis being named in the squad.

The Senegalese Football Federation's general secretary Victor Seh Cisse believes the reasons given by Watford for objecting to Sarr's call-up are not justified.

"By mail on Friday, December 31, Watford notified on the basis of arguments equally specious as fallacious its decision to block the player Ismaila Sarr, who has expressed his desire to join the Senegalese selection for the next Cup of Nations in Cameroon," a statement read.

"The Senegal Football Federation wishes to express with this communication its deep condemnation of the disrespectful, pernicious and discriminatory behaviour of Watford's hierarchy who look by all means to prevent a player from playing with his national team."

Clubs have until Monday to release players called up by their national teams for the delayed competition, which has been pushed back by a year due to coronavirus.

Senegal, who finished runners-up to Algeria in 2019, added they will take the matter up with FIFA should it not be resolved. 

Responding to the allegations, Watford released a statement on their official website on Sunday that read: "Ismaila Sarr suffered a knee ligament injury on November 20 in the match against Manchester United and has not been fit to play for Watford FC since that date.

"In early December, the club wrote to the Senegal Football Federation outlining the clinical diagnosis of Ismaila's injury and immediately followed that up by supplying the MRI scans detailing the extent of the injury. 

"After further consultation with medical experts, we informed the federation of Ismaila's rehabilitation process and likely timeframe of recovery.

"Within the past 10 days, the club has reiterated to the Senegal Football Federation the player's current medical status and recovery schedule.

"The Hornets have also invited the Senegal Football Federation to instruct their own independent surgeon to confirm the diagnosis and rehabilitation period."

Holders Algeria have been grouped alongside two-time winners Ivory Coast following the 2021 Africa Cup of Nations draw ceremony held in Yaounde on Tuesday.

The delayed event, which will be hosted in Cameroon from January 9 to February 6, features 24 teams for the second time with six groups of four.

Algeria, who triumphed in Egypt in 2019, are alongside 1992 and 2015 winners Ivory Coast as well as Sierra Leone and Equatorial Guinea in Group E.

Hosts Cameroon will open the tournament in Group A, where they were drawn alongside Burkina Faso, Ethiopia and Cape Verde.

Record seven-time winners Egypt, who last lifted the title in 2010, are grouped with three-time champions Nigeria, Sudan and Guinea-Bissau in Group D.

Arsenal team-mates Pierre-Emerick Aubameyang and Thomas Partey will face off in Group C with Gabon and Ghana alongside first-timers Comoros and top seeds Morocco.

Debutants Gambia are alongside Tunisia, Mali and Mauritania in Group F, while 2019 runners-up Senegal are in Group B with Zimbabwe, Guinea and Malawi.

Africa Cup of Nations draw:

Group A: Cameroon, Burkina Faso, Ethiopia, Cape Verde

Group B: Senegal, Zimbabwe, Guinea, Malawi

Group C: Morocco, Ghana, Comoros, Gabon

Group D: Nigeria, Egypt, Sudan, Guinea-Bissau

Group E: Algeria, Sierra Leone, Equatorial Guinea, Ivory Coast

Group F: Tunisia, Mali, Mauritania, Gambia