The form of the club’s record signing has deteriorated rapidly in recent weeks and a number of high-profile errors led to Lampard selecting Willy Caballero in his place.
Chelsea spent £72million 18 months ago following the departure of Thibaut Courtois, but Lampard denied Kepa’s price tag came into consideration when contemplating whether or not to drop him.
“The reaction has been good as I would expect,’ said Lampard at his pre-match press conference. “I haven’t had lots of conversations with him. It’s a decision I will have to make.
“It doesn’t matter when you came to the club, I don’t take into account the fee. It’s the training that counts.
“It wasn’t about giving him a jolt. It was just a selection on that day. I want everyone’s reaction spot on. I know how it will feel for him. I had it in my career, it is part and parcel. I am pleased with the reaction.
“I deal with the players as it feels right. I am open and straight with them.”
Lampard, who has been linked with moves for the likes of Dean Henderson and Andre Onana, meanwhile, refused to confirm which of his two senior goalkeepers would start on Monday.