Thibaut Courtois and Petr Cech will be hoping to have done enough to convince Mourinho that they should get the nod for Monday's clash at Turf Moor.
Belgium number one Courtois played the full 90 minutes on Tuesday as the London club rounded off their pre-season schedule with a 2-0 win over Real Sociedad.
Mourinho revealed that there was no need to read too much into that, as he was merely ensuring Courtois got some match practice after recovering from injury.
The Chelsea boss refused to divulge which of the two will start against Sean Dyche's newly promoted side and will only inform the players on Sunday.
He said: "I played Thibaut for 90 minutes because he was injured and didn't play last weekend.
"Petr played two matches in Turkey and the first half against Ferencvaros. Since he arrived Courtois has only played 45 minutes against Werder Bremen, he needs to play.
"The fact Courtois played 90 minutes wasn't me saying he's first choice for Monday, it's because he didn’t play the last three matches. The players don't know (who's first choice). When will I tell them? On Sunday."
