McCall could face a major rebuilding project in the summer with the likes of Darren Randolph, Tom Hateley, Nicky Law, Chris Humphrey, Jamie Murphy and Michael Higdon coming to the end of their deals.
And he feels a replay victory over Aberdeen at Fir Park on Tuesday, which would set up a fifth-round clash at Hibernian, could help strengthen his hand.
McCall, who is in discussions with the club over his own contract, said: "Looking at the long picture, it would be fantastic if we could go as far as we can in the cup, do well in the league, and maybe use that as a carrot to try to keep some of the players.
"Nobody thought we could have kept Steve Jennings for another year (in 2011), everyone thought he was down south and gone but we managed to keep hold of him for another year.
"Hopefully that will be the same with two or three of the lads who everyone expects to leave.
"If a few of them leave, they will want to go out on a high. There is no better high than to play in the the last game of the season in a cup final.
"We're not looking too far ahead. Aberdeen are a very tough opponent to get over, and the winners go to Hibs, which is obviously another difficult game.
"But there is a sense in the squad that they want to do as well as they can.
"I sometimes find it, maybe not amazing, but some of the criticism the players get at times...Why people think we should be above other sides is beyond me when you look at the squad.
"These lads have been absolutely outstanding, the contribution over the last three or four years has been terrific.
"They give everything they have. Some days they might not be at their best, other days they can turn it on.
"I've got belief in them and I hope tomorrow the Motherwell fans turn out and get behind us.
"I'm sure the fans realise how big a game it is and we can do with a big following to roar us on."
Motherwell have reduced prices to £12 and £6, with season ticket holders allowed in free, in a bid to get that backing.
They hope to offset the losses with an extended cup run in order to plug the gap from the absence of Rangers from the Clydesdale Bank Premier League, but McCall is more focused on the experience and potential glory.
"For most clubs the financial aspect is good," said McCall, who led Motherwell to the 2011 final, where they lost to Celtic.
"But we have got players in that dressing room who have been to Hampden three times in the last couple of years. It's a great place to play football.
"We have had a little bit of success a couple of seasons ago and naturally we want to do it again."
Motherwell have only lost once in 13 games against Aberdeen, although that defeat came in last season's quarter-finals at Fir Park.
McCall dismissed the history as irrelevant, although he believes Saturday's 3-2 victory over Ross County, their first home win in more than three months, was crucial.
"I think we needed that win psychologically," said McCall, whose side have twice lost injury-time equalisers against Aberdeen this season.
"Everyone has kept talking about our home form.
"It has certainly done us good, the pressure is off a little bit in that regard. The players are maybe not as anxious or tense.
"As much as you can talk all you want, sometimes little demons in the back of your head can tell you different things.
"But I don't think what's gone on previously will have any bearing - I think it will be a very tight game."