Chelsea boss Thomas Tuchel explained substituting Romelu Lukaku in victory at Brentford.

Lukaku again drew a blank on the day.

Frank said, "I just felt him a bit tired. Honestly today I thought we did altogether a very strong 65 or 70 minutes, including Romelu and Timo.

"I'm not concerned, I felt him a bit tired and then isolated because we were together as a block defending too deep and both of them, Timo and Romelu, were a bit too far away to help us to escape the pressure. So that was a bit of a problem today, but no concern.

"Normally the best thing is if he scores but he is very unselfish at the moment looking for Timo in good situations and when we had them in those situations there were some close offside decisions. So there is no need to worry."