Saints' eight-game unbeaten run came to an abrupt end when they suffered a 5-0 defeat by Celtic in the Scottish Communities League Cup quarter-finals in the east end of Glasgow. The McDiarmid Park boss is looking for a positive reaction from his players on Saturday when the Steelmen visit in the SPL.
"First and foremost I look at myself to see if I could have done anything better and I possibly could, I could have gone with a different shape," Lomas said.
"The players are honest enough, though, to realise they didn't play too well.
"We have always been pretty competitive against Celtic but we weren't good enough on and off the ball.
"But we have to put it aside, learn our lesson and go again on Saturday.
"There is no point in moping about. We have to pick ourselves up because we have a massive game against Motherwell.
"We know it ain't going to be easy. Motherwell are a decent team with decent players and if you look at them you understand why they did so well last year."