Portuguese winger Cristiano Ronaldo may return after injury for Manchester United when the English champions begin their Champions League defence in their opening Group E encounter against Villarreal tomorrow.
"Ronaldo is training now, he's with the first team. He's come on leaps and bounds and I may take him with us tomorrow, who knows?" manager Alex Ferguson said.
United, aiming to become the first club to win consecutive Champions League titles since the elite competition was reformed in 1992, will be without the suspended Paul Scholes and midfielder Michael Carrick, who injured his ankle on Saturday.
In the other Group E match tomorrow, Scottish champions Celtic are favourites to win their opening home match against Danish Champions League debutants AaB Aalborg.
Liverpool will hope to capitalise on their first league win over United under coach Rafa Benitez when they travel to Olympique Marseille this evening.
"Now we will go to Marseille in a good frame of mind. That was our best performance of the season and we now feel we can go into a Champions League in good heart and spirit," Benitez said.
The 2005 Champions League winners have fitness concerns over captain Steven Gerrard, Fernando Torres and Javier Mascherano.
Gerrard was a second half substitute on Saturday after a groin operation while Spanish international Torres stayed on the bench after suffering a hamstring injury at the end of last month. Mascherano limped off with a calf problem.
Marseille met Liverpool in the group stage last season, winning 1-0 at Anfield before being thrashed 4-0 at home. Also in Group D, Dutch champions PSV Eindhoven host Atletico Madrid.
Chelsea, beaten by United on penalties in this year's Champions League final in Moscow, have a home tie against Girondins Bordeaux and will be buoyed by the return of Michael Ballack.
"He will play on Tuesday (today) but I do not know whether it will be for 45 minutes, 60 or 70," Chelsea manager Luiz Felipe Scolari said.
The return of the German captain, who has not played since Aug. 24 and missed the start of his country's World Cup qualifying campaign, is a welcome boost for the Londoners who must navigate Group A without injured midfielder Michael Essien.
England's remaining representatives Arsenal launch their Group G assault away to Dynamo Kiev tomorrow with Porto at home to Fenerbahce in the same group.
Barcelona were dealt a blow ahead of their Group C opener at home to Portugal's Sporting today when Aleksander Hleb was ruled out for three weeks after spraining his left ankle in his side's 1-1 draw against Racing Santander.
Nine-times champions Real Madrid have no major injuries ahead of their Group H opener against Belarussian debutants BATE Borisov tomorrow after scraping a 4-3 win over Numancia.
Italian champions Inter prepared for their Group B trip to Greece's Panathinaikos with a 2-1 win over Catania, while fellow Italians Fiorentina were beaten 2-1 by Napoli ahead of their Group F match at French champions Olympique Lyon.