The win over the German side on Thursday is widely expected to have had a draining effect on the championship chasers.

But manager Dick Advocaat is reluctant to freshen up his side unless it is really necessary.

Stephane Guivarc'h, the new £3.5m signing from Newcastle, is likely to be on the bench.

Keeper Lionel Charbonnier will have to be replaced after picking up a knee injury on Thursday.

He may miss the rest of the season and will be replaced on Sunday by Finn Antti Niemi.

Rangers face a punishing run of seven games in just over 23 days and the Dutch boss is concerned about the effect the schedule will have on his squad.

Advocaat said: "The game against Leverkusen took a lot of energy out of the team.

"We have a lot of games to come in the league and the UEFA Cup, not to mention the League Cup final."

Sunday's match is a rehearsal for that game and Advocaat knows it will not be easy.

"This will be a difficult game against St Johnstone. I saw them defeat Hearts in the League Cup semi final. They are a good side and they work very hard," he said.

Scotland midfielder Barry Ferguson faces a fitness test on his damaged ankle if he is to face the in-form Perth side.

Saints are set to name the same team for the sixth successive match and are anxious to put on a show in front of the cameras.