Chelsea are considering playing André Schürrle as a central striker in Sunday’s trip to Manchester United after Loïc Rémy joined Diego Costa on the sidelines, with the pair struggling with groin injuries.

Rémy sustained an injury while scoring his team’s opening goal in the 6-0 midweek rout of Maribor in the Champions League and underwent scans on Wednesday to ascertain the extent of the damage. Despite the player having been initially optimistic as to his chances of featuring at the weekend, the results of those tests have confirmed he will be out for up to two weeks.

His absence is particularly untimely given Costa’s fitness issues. The Spain forward, who has been hampered by hamstring trouble all season, was hospitalised briefly with a stomach virus after complaining of cramps this week but, more seriously, is suffering from a groin strain apparently picked up on international duty this month. He has failed to train properly since returning to London after the Euro 2016 qualifiers against Slovakia and Luxembourg, of which he played all but eight minutes.

José Mourinho had been cryptic as to the nature of Costa’s absence for Saturday’s victory at Crystal Palace but did suggest the £32m signing from Atlético Madrid had yet to overcome the hamstring problem. But, while that complaint would have required a period of rest to be cured – he has missed his team’s past two games and will effectively have sat out a fortnight by the time the team visit United – the 26-year-old needed intensive treatment this week on the groin injury.

That remains the main concern and, having been unable to take part in training, there is an acceptance within the club’s medical staff that it is unlikely Costa will be able to feature at all at Old Trafford. Indeed, there is intense frustration at Cobham that a player who had been managing the hamstring complaint before the international window, scoring nine goals in seven Premier League appearances, returned from the Spain squad with an additional complaint.

The pair’s absence would leave Didier Drogba, who has suffered ankle injuries this term and admitted in midweek that he was short of match fitness, as the team’s only fit senior forward against Louis van Gaal’s team. The Ivorian veteran scored the first goal of his second spell at the club in the victory over Maribor, from the penalty spot, but has not started a Premier League game since returning to English football from Galatasaray.

Instead, Mourinho is exploring the possibility of starting with Schürrle as his principal forward at Old Trafford now that the World Cup winner has recovered from the bout of flu which had ruled him out of Germany’s Euro 2016 qualifier against Scotland last week. Schürrle began the corresponding fixture last season up front, with Mourinho much criticised for failing to field an out-and-out striker in his lineup as the game finished goalless, and a repeat remains an option.

There is concern that Drogba, 36, would not be able to play 90 minutes at this level given his fitness concerns. The hugely promising teenager Dominic Solanke, who made his senior Chelsea debut as a substitute on Tuesday, is likely to be included in the squad which travels to Manchester and represents another alternative.