Chelsea suffered an injury scare in training on Wednesday after Diego Costa pulled up with a hamstring injury, though the severity of the strain remains to be determined.

The Spain international, a £32m signing from Atlético Madrid this summer, will undergo further tests at Cobham and while the initial prognosis appeared grim, there are hopes the injury will not prove as severe as first feared.

The 25-year-old has scored in each of his first two appearances in the Premier League and has swiftly established himself as first-choice and a key member of José Mourinho’s preferred line-up.

Although Chelsea have not written off his chances of featuring at Everton on Saturday, even if the injury rules the Brazil-born forward out for the forseeable future they may sanction Fernando Torres’s mooted loan move to Milan.

Torres is receptive to the possibility of joining Milan, though talks between the Italian club and Chelsea have yet to reach agreement over the Spaniard’s wage package. The striker, who moved from Liverpool for a then British record £50m in January 2011, has two years to run on his £175,000-a-week contract and is unwilling to take a pay cut if he departs Stamford Bridge. Yet having rarely thrived over his three years at the club, there is a recognition that he will only ever play a fringe role at Chelsea after falling behind Costa and even the veteran Didier Drogba in the pecking order.

“Our goal is to take a great striker,” said Milan’s vice-president, Adriano Galliani. “We will see if we achieve our aim, but Fernando Torres? He is a great striker. We are actively working.”

Should Torres leave, Chelsea would seek to add a third senior forward to their ranks before the transfer window closes on Monday, with interest established in Roma’s Mattia Destro and, more intruigingly, the Monaco striker Radamel Falcao.

Falcao is effectively available for loan and would be open to a move to London, even though loan fees and wages combined would see a season-long switch cost around £20m. Chelsea have long coveted Falcao, who shares his agent, Jorge Mendes, with Mourinho.