Antonio Conte has urged Chelsea striker Alvaro Morata to work hard and rediscover his best form.
However, the last of those came against Brighton & Hove Albion on Boxing Day, with the former Juventus man going scoreless across 10 appearances in all competitions while grappling with a back injury.
"He has to work and to recover the best form after an injury in his back," Conte told reporters ahead of Sunday's trip to face league leaders Manchester City.
"He has to work and have patience and we must have patience. But the only way is to work."
While the jury remains out on Morata, Ross Barkley has had little to celebrate in Chelsea colours since joining from Everton in January.
He was substituted on his only start in three senior appearances, the shock 3-0 defeat at home to Bournemouth in January, while the 24-year-old's hamstring injury curse has struck again.
Even though Barkley is now back in training, Conte was in no mood to offer any guarantees ahead of facing Pep Guardiola's in-form side.
"Ross Barkley, in this week he trained with us. Now he has recovered from his injury and he will come with us for Manchester City," the Italian added.
"Then I don't know if I decide to find a place on the bench for him or in the stand for another week."