Chelsea expect to be bolstered by the return of Didier Drogba for the second leg of their Champions League semi-final in Barcelona on Tuesday night despite the Ivorian still being troubled by a knee injury sustained during last week's narrow victory over the holders.

Drogba, whose goal at Stamford Bridge supplied the lead to which Chelsea will cling at Camp Nou, missed yesterday's goalless draw at Arsenal while he underwent treatment at the club's Cobham training centre. The 34-year-old will be assessed again on Sunday but, while the interim first-team coach, Roberto Di Matteo, was publicly cautious of his chances of featuring in the return, there is private confidence that the striker will be fit to lead the line in Barcelona.

"At this moment of time, I don't know," said Di Matteo when asked about Drogba's prospects. "We'll have to assess the players over the course of the weekend. He has an injury on his knee, which is why he did not play here, so it's whether the progression on this injury will be quick enough [for him to feature]."

The draw at the Emirates Stadium maintained Di Matteo's impressive record since taking over from André Villas-Boas seven weeks ago, with Chelsea having lost only one of his 14 games in charge. The Italian claimed the point was "one more gained towards us reaching fourth place" with Chelsea, albeit still in sixth, having three home games and a trip to Liverpool as their remaining fixtures.

Indeed, the sense of frustration here was endured by Arsène Wenger at what he deemed to have been "a very unfair result" after his team struck the woodwork twice and had claims for a penalty for Gary Cahill's push on Robin van Persie turned down. Arsenal are likely to be without their winger Theo Walcott for the remainder of the domestic campaign after he damaged a hamstring in the second half and had to be replaced on the hour-mark, though Wenger suggested the injury would not affect the player's chances of featuring at Euro 2012.

Walcott had initially tried to run off a tweak in his thigh before sustaining further damage to the hamstring near the touchline. The winger, a surprise omission from Fabio Capello's squad for the World Cup finals in 2010 and watched here by the interim national coach, Stuart Pearce, will undergo a scan on Sunday to determine the extent of the damage.

"It looks like a serious hamstring injury," said Wenger. "We assessed the hamstring [after he felt it the first time] but he wanted to stay on the pitch. I think he should have come off straight away because, the second time, it was a real hamstring [injury]. For him, it'll be tough to come back for us before the end of the season. A serious hamstring injury needs a minimum of 21 days for a recovery. He should be OK to play for England – he'll just have a good rest."