The former Queen of the South man has yet to feature in a competitive clash for the Light Blues following his switch to Ibrox this summer.
The Gers can only use Clark and keeper Cammy Bell as trialists against the Fifers after Nicky Law and Jon Daly appeared in their third league fixtures of the season against Aidrieonians last Friday.
McCoist said: "Nicky will come into our plans at the weekend. He has been training really well and has showed up well in one or two of our closed-doors games.
"His return is very timely because against Berwick we effectively finished with Fraser Aird and Barrie McKay at centre-forward for us.
"You don't need to be a rocket scientist to work out that that isn't ideal."
The champions head into their second home league fixture of the campaign with a perfect record and a hat-trick of terrific League Two performances under their belt so far.
And McCoist hopes his former strike partner and now Light Blues Under-20 coach Gordon Durie can give him the low-down on Willie Aitchison's side following his spell in the New Bayview hotseat.
"Gordon knows the players at East Fife better than most of us here do," McCoist told rangers.co.uk
"His son Scott is one of them and he spent time here when he was younger, but he got sent off last weekend against Arbroath and will be suspended.
"Gordon covered that game and we've had them watched a couple of other times as well.
"We have been talking to Gordon a lot about the opposition and hopefully that gives us an added advantage."