AC Milan and Arsenal hope to rediscover their best form for Tuesday's Champions League last-16 second leg after both sides showed signs of weariness.
The first leg in London two weeks ago finished 0-0, one of a number of fitful draws the pair have managed lately.
European champions Milan drew 1-1 at home to Lazio to stay fifth in Serie A on Saturday, having drawn three times in the league in February after injuries stalled a mini revival.
World player of the year Kaka has missed the last two games with a knee problem but is expected to face Arsenal. A Milan spokesman said British media reports that the Brazil playmaker had been ruled out were not true.
Alessandro Nesta and Andrea Pirlo will return but Clarence Seedorf is a big doubt after going off injured against Lazio, with Emerson and left back Marek Jankulovski set to miss out.
"Kaka is doing very well. Pirlo and Nesta will certainly be back in time for Tuesday's game," coach Carlo Ancelotti said.
"I don't think the physical aspect is the most important thing to win in Europe right now. For this reason I think we should go for it against Arsenal."
His main selection headache will be who to play up front, having surprisingly opted for 18-year-old Alexandre Pato as a lone striker at the Emirates in the first leg.
Paolo Maldini, 39, has been used sparingly in his final season before retirement but looks certain to play in what could be his last European game.
LESS PLEASED
English league leaders Arsenal grabbed a last-gasp goal in Saturday's 1-1 home draw with Aston Villa and will be happy with the same result on Tuesday as it would put them through.
Manager Arsene Wenger has been less pleased with their recent displays, with the serious injury to striker Eduardo da Silva during the 2-2 draw at Birmingham on Feb. 23 having an effect. Their lead in the Premier League has been cut to one point.
"We had a hangover from last week definitely. You could see that in the first half," Wenger said after the Villa game. Everyone goes through a bad spell."
Striker Emmanuel Adebayor, who hit the bar with a stoppage-time header in the first leg, has gone off the boil recently but is certain to start at the San Siro.
Wenger may decide to play him up front on his own given the nature of the tie and a lack of other options. Dutch forward Robin van Persie could make the bench after persistent injury.
Tomas Rosicky and Kolo Toure look set to miss out with hamstring and calf problems.
Teams (probable):
Milan: 16-Zeljko Kalac; 44-Massimo Oddo, 13-Alessandro Nesta, 3-Paolo Maldini, 4-Kakha Kaladze; 8-Gennaro Gattuso, 21-Andrea Pirlo, 23-Massimo Ambrosini; 22-Kaka, 7-Alexandre Pato, 9-Filippo Inzaghi.
Arsenal: 24-Manuel Almunia; 3-Bacary Sagna, 6-Philippe Senderos, 10-William Gallas, 22-Gael Clichy; 27-Emmanuel Eboue, 4-Cesc Fabregas, 19-Gilberto Silva, 16-Mathieu Flamini, 2-Abou Diaby; 25-Emmanuel Adebayor
Referee: Konrad Plautz (Austria)