Rangers manager Walter Smith says David Weir will return to the side to face Celtic in midweek after the captain was left on the bench against St Johnstone."Davie had sickness prior to the game in Portugal, where he still played for an hour," Smith told BBC Scotland. [LNB]"I just felt it was better to leave him out today and we can get him back again on Wednesday." [LNB]Nikica Jelavic scored two and Sasa Papac and Kyle Lafferty also chipped in to seal a 4-0 win for Rangers at Ibrox. [LNB]The win, which came after Celtic were beaten 2-0 by Motherwell, means Rangers trail their Glasgow rivals at the top of the Scottish Premier League table by five points with two games in hand. [LNB]"We're pleased with the result," said Smith. "We played very well in the first half and we dictated play for most of it.[LNB] [LNB][LNB] "We restricted St Johnstone's chances, with Allan McGregor only needing to make one good save. [LNB]"In the second half, St Johnstone made one or two little changes and they pushed us back for 25 minutes. [LNB]"But we managed to claw ourselves back into the game and the third goal effectively killed it. [LNB]"It meant we could go on and finish strongly and we're delighted with the result." [LNB]Slovakian winger Vladimir Weis was forced to leave the field in the first half of the match, but the Rangers manager said his ankle knock was not serious. [LNB]Rangers travel to Celtic Park on Wednesday for their Scottish Cup fifth-round replay.