The 36-year-old former Scotland full-back has been one of the pillars of the United defence despite his advancing years. However, Malpas has been troubled with a groin injury and faces a late fitness test.
There is mounting speculation that this will be Malpas' final season - he is already on the coaching staff at Tannadice. But Sturrock said: "He's got another year on his contract, so don't write him off just yet. He has been among the three best players for this club this season and obviously I am hoping he plays on Saturday. He is a tremendously influential player. You only have to look at the way he played against Celtic recently."
Sturrock's side go into the match on the back of a 3-1 Premier League home defeat to Hearts, which increased their relegation worries. Celtic, meanwhile, romped to a 5-0 defeat of Dundee at Celtic Parklast weekend and are now only six points behind the leaders, Rangers.
Sturrock has other worries over his line-up, with David Hannah, Brian McLaughlin and Scott McCulloch all ineligible, while John Eustace is suspended. United's Dutch goalkeeper, Sieb Dykstra, said: "The defeat by Hearts has obviously affected our confidence but this is a one-off game."
Celtic could welcome back their influential Slovakian midfielder Lubomir Moravcik, who has been out of action recently with a hamstring injury. They will be without the suspended Johan Mjallby and Vidar Riseth, which could mean the Danish international Morten Wieghorst, who has been out all season with a knee injury, could return in a defensive role, with Alan Stubbs ruled out and Enrico Annoni doubtful.
Tomorrow St Johnstone face Rangers in the other semi-final at Celtic Park, in a repeat of this season's League Cup final. Rangers won that game 2-1 and they also thrashed the Saints 7-0 in a League fixture in Perth earlier this season.
Last weekend, however, the Saints gained some revenge with a 3-1 League victory at McDiarmid Park. "We played very well," Roddy Grant, the St Johnstone striker, said. "We got at them and I don't think they could handle it. That's the way you have to play Rangers. If everyone wins their individual battles all over the park, then you are in with a chance."
Rangers welcome back the influential Scotland defender Colin Hendry and the unsettled French striker Stephane Guivarc'h into the squad, after ankle and hamstring injuries respectively.Reuse content