Chelsea head coach Liam Rosenior says goalkeeper Robert Sanchez was "really disappointed" to be left out of Wednesday's match against Aston Villa, but stressed he does not have an established number one.

Spain international Sanchez was criticised for both his distribution and errors at set-pieces during Sunday's 2-1 defeat at leaders Arsenal.

Rosenior brought in Denmark's Filip Jorgensen - Sanchez's long-term understudy - for the 4-1 victory at Villa Park.

"I've been really honest with Rob," he said. "He was really disappointed not to play, which is what I expect from every player, whether they're a goalkeeper or an outfield player.

"But the way Rob responded in training, the way he supported Filip - in the warm-up, in the dressing room - was magnificent."

Chelsea have a long-term strategy of encouraging squad rotation, and Rosenior intends to apply that principle to his goalkeepers too.

"For me, genuinely, I look at the goalkeeper position differently for each game," he said. "I want there to be competition in every area of the pitch.

"I know, traditionally, if there's a change of goalkeeper, people assume he's...