Liverpool's need for defensive reinforcements was always likely to dominate the headlines on transfer deadline day and so it proved as the Premier League champions made two late signings.

Centre-back Ben Davies arrived from Preston North End, while Liverpool made a further addition to the heart of their backline with the loan signing of Ozan Kabak from Bundesliga strugglers Schalke until the end of the season.

Those signings came on a day that saw Joel Matip ruled out for the rest of the season with an ankle ligament injury. Virgil van Dijk and Joe Gomez are long-term absentees and Liverpool were forced to play Jordan Henderson and Nathaniel Phillips at centre-back in Sunday's win at West Ham.

Heading for the Anfield exit door is Takumi Minamino, the forward moving to Southampton on a six-month loan deal having only joined Liverpool last January.

It came after Southampton loaned veteran Shane Long to promotion-chasing Championship side Bournemouth.

Bournemouth also sanctioned the departure of Joshua King to Everton for a nominal fee until the end of the season.

There were outgoings at Arsenal as well, with Shkodran Mustafi signing for Schalke on a short-term deal and Joe Willock going on loan to Newcastle United, who let DeAndre Yedlin leave for Galatasaray.

Arsenal also sent Ainsley Maitland-Niles to West Brom on loan.

Turkish giants Galatasaray acquired Gedson Fernandes on a temporary deal from Benfica following an unsuccessful stint at Tottenham.

In Serie A, Parma landed Bayern Munich's teenage forward Joshua Zirkzee in a loan deal that contains the option to sign the 19-year-old permanently.

Atalanta are firmly in contention for a top-four finish in Serie A and bolstered their ranks for that push with the capture of Ukraine midfielder Viktor Kovalenko from Shakhtar Donetsk.

Roma can afford to have hopes of a title challenge and brought in teenage full-back Bryan Reynolds from MLS outfit Dallas on an initial loan deal, with an obligation to buy, to help them.

Frozen out at Juventus, midfielder Sami Khedira is back in the Bundesliga following a switch to Hertha Berlin, but one of European football's most exciting talents is heading to Italy after Udinese signed Jayden Braaf on loan from Manchester City with an option to buy.

Elsewhere, Everton defender Jonjoe Kenny joined Celtic on loan for the rest of the season, Brighton and Hove Albion signed highly rated midfielder Moises Caicedo from Independiente del Valle, West Brom loaned Okay Yokuslu from Celta Vigo and defender Teden Mengi moved from Manchester United to Wayne Rooney's Derby County on a temporary basis.

Celtic confirmed on Monday that manager Neil Lennon and 13 senior players are self-isolating, but the club are still defending the decision to hold a training camp in Dubai.

Defender Christopher Jullien tested positive for COVID-19 after the team returned to Scotland ahead of Monday's Premiership clash with Hibernian.

Although all other squad and staff members returned negative tests, Lennon, assistant John Kennedy and 13 first-team players are self-isolating after being deemed close contacts.

The reigning champions remain insistent they followed "rigorous" COVID-secure protocols and that the threat of contracting the virus would have been similarly high had they stayed in Scotland.

In a statement, Celtic said: "Clearly we are hugely disappointed, as we know our supporters will be. The contacts were identified during the period from Wednesday last week, primarily around flight and team coach travel, during which time Celtic applied the same rigorous protocols used for pre-season training camps, UEFA match travel and for all domestic match arrangements in Scotland.    

"These protocols have served us well in the past, as the club has not had one positive case in our own 'bubble' until now. As we have already stated, Celtic's decision to travel to Dubai for a training camp was for performance reasons. Whilst we were in Dubai, the announcements made on January 4 significantly changed the COVID landscape.  

"The reality is that a case could well have occurred had the team remained in Scotland, as other cases have done in Scottish football and across UK sport in the past week.
 
"Celtic has done everything it can to ensure we have in place the very best procedures and protocols. From the outset of the pandemic, Celtic has worked closely with the Scottish Government and Scottish football and we will continue to do so."

Rangers took a huge step towards winning the Scottish Premiership title as Callum McGregor's own goal gave them a 1-0 Old Firm derby win over Celtic.

Steven Gerrard's unbeaten team now lead their fierce rivals by a formidable 19 points at the top of the table.

Celtic still have three games in hand but their hopes of clinching a historic 10th straight title look increasingly slim, with this result piling the pressure on manager Neil Lennon.

Champions Celtic had the better of Saturday's match at Ibrox, but the tables were turned when Nir Bitton was sent off after 62 minutes.

Callum McGregor then inadvertently gave Rangers, who did not register a shot on target in the contest, a priceless winning goal.

Celtic made an excellent start and it took two pivotal saves from goalkeeper Allan McGregor to stop the visitors from going into an early lead.

He impressively got down low to deny Odsonne Edouard, who had not played in the last meeting between the sides, which Rangers won 2-0 in October.

The Rangers keeper then produced an even better fingertip stop to tip a 25-yard shot from Leigh Griffiths that was destined to find the top corner onto the post.

Gerrard brought on Ianis Hagi – who had been dropped from the starting XI in place of Ryan Kent – at half-time, with Kemar Roofe coming off and his side gradually began to improve.

Rangers got a big boost when Bitton was dismissed after wrestling Alfredo Morelos to the ground as the striker attempted to race on to a James Tavernier pass and looked like he had a clear path to goal.

They moved in front after 70 minutes, Joe Aribo flicking a Tavernier onto Callum McGregor, whose arm deflected the ball beyond Vasilios Barkas.

Celtic substitute Mohamed Elyounoussi shot just over but there was no way back for the 10 men, who have now lost three straight league derbies for the first time since 2008.