Romelu Lukaku will pay the penalty for West Brom

The teenager bagged his 13th goal of the season in the 2-1 win against Swansea on Saturday but then missed a penalty to put his side ahead before Jonathan De Guzman's own-goal sealed the win.

And Clarke believes the on-loan Chelsea man, who has revealed he does extra training every day, will focus on spot-kicks this week.

Clarke said: "I'm sure he'll spend all next week practising penalties. But, who knows, he might not get the next one. We have got one or two lads who are ready to step in.

"Romelu is improving all the time. Playing is good for him, which is why he came here.

"It's been good for us because he's made a big contribution, and it will be good for Chelsea in the future."

Meanwhile, Clarke admitted his side were lucky to survive a late scare when Swans substitute Roland Lamah had a goal ruled out incorrectly for offside.

Replays showed Lamah received the ball from ricochets off Albion players.

And Clarke admitted: "The goal definitely should have been given, the ball came off Ben Foster last.

"It's fortuitous, but sometimes when you put in the effort, energy and quality we put into that game you probably earn that bit of luck.

"We deserved to win the game. When we missed the penalty we were in total control of the game. I felt we had a good momentum and we didn't allow it to upset us and we just kept playing.

"We got ourselves in front and I thought, by and large, with the exception of the disallowed goal, we controlled the game quite well."