Chelsea manager Jose Mourinho says a number of key players will undergo a late fitness test ahead of this afternoon's game against Arsenal.
Midfielder Willian is ruled out after suffering an injury in mid-week against Maccabi Tel Aviv and Pedro, Falcao and Oscar are all doubtful and could be forced to sit out the key game at the Emirates.
"I select every player for the squad because we have doubts," Mourinho told reporters.
"Tomorrow I don't want to be in a situation where during the warm-up somebody doesn't have the best feelings, and we have lots of players in this situation.
"Willian is not even an option. Pedro, Falcao and Oscar - let's see what happens. They are not definitely ruled out but let's see."