Tadej Pogacar beat Roglic by 59 seconds to win the Tour last month as the Slovenian duo recorded a remarkable one-two for their country.
Roglic, who has reached the podium at all three Grand Tours, goes into the Vuelta as the man to beat, having won by two minutes and 33 seconds over Alejandro Valverde in 2019.
Froome, Valverde, Tom Dumoulin, Richard Carapaz, Thibaut Pinot and Enric Mas will all be hoping to challenge.
Ahead of the event, which starts with a stage from Irun to Arrate on Tuesday and runs until November 8 with the finish in Madrid, we take a look at the biggest talking points with the help of Opta data.
A DIFFERENT YEAR
As well as clashing with the conclusion of the Giro d'Italia, which runs until October 25, due to coronavirus-related rescheduling, this year's Vuelta has some other key differences.
For the first time since 1985 there will be fewer than 21 stages, with just 18 in the 2020 race across a 2,882-kilometre route.
Irun will host the start of the race for the time, while it was 1961 when La Vuelta last began in the Basque Country.
SPANISH DOMINANCE WANING
Historically, home riders have thrived at the Vuelta, with Spanish participants winning on 32 of the 74 occasionsthe race has been run. France and Belgium are the next best nations on nine and seven respectively.
However, a Spaniard has not taken the red jersey since Alberto Contador triumphed in 2014, the country's longest drought since 1992-1997 (six races).
The dry spell came after Spanish riders had won eight of the first 10 Vueltasin this century. Now, Contador's 2012 and 2014 wins are their only triumphs in the last 10.
On the plus side, a Spanish rider has won a stage at every Vueltaapart from in 1996.
THE CHALLENGE FACING ROGLIC
Roglic is looking to defend his crown, but no rider as achieved that at this race since Roberto Heras' triumphs between 2003 and 2005. The Team Jumbo-Visma star also faces some stiff competition.
INEOS Grenadiers rider Froome is the last rider to have won multiple editions of La Vuelta, doing it so in 2011 and 2017 – the longest span between two wins among all riders with multiple titles.
He will now look to join Heras (four wins), Tony Rominger (three) and Contador (three) among the Vuelta greats.
Valverde has finished on the Vuelta podium a remarkable seven times in 13 appearances (2003, 2006, 2009, 2012, 2013, 2014 and 2019), the most of all time.
He has 10 top-five finishes, although 2009 was his only win. This will be the veteran's 14th participation, more than any other active rider.
Mas finished second in his last outing in 2018, when he also finished as best young rider.
The Movistar rider comes into the race with some form – he was fifth at the Tourand came second in the young riders classification behind only the yellow jersey winner Pogacar.
Pinot has been in the top 10 in each of the two Vueltas he has managed to finish, though he has abandoned in a Grand Tour seven times, which is more often than he has reached the end (six).
Dumoulin has been in the top 10 in each of the last five grand tours he finished, while Carapraz has two major top-five results to his name, though is yet to finish higher than 18th in Spain.
POINTS JERSEY UP FOR GRABS
Roglic and Froome won the points jersey as well as the overall classification in their 2019 and 2017 triumphs – prior to those doubles, that feat had not been achieved since 2000.
Along with the challengers for overall glory, sprinters Sam Bennett and Pascal Ackermann are among the top contenders for that honour at this event.
Irishman Bennett has seven stage wins at Grand Tours, while German Ackermann won the points classification in the only previous Grand Tour he took part in, the 2019 Giro.