The Well gaffer saw Aberdeen knock his side out of the William Hill Scottish Cup on Tuesday, and insists the Steelmen must now bounce back with a win away to Hibs on Saturday.
With many players in the Well squad out of contract in the summer, the manager also stated a desire to see any potential leavers depart the club on a high, and went on to voice his hopes of another European campaign next year.
McCall said: "The challenge for us and in particular this group of players is to go on and finish as high as we possibly can.
"Celtic are out on their own to a certain extent but we have to look to really kick-on and respond to the cup exit.
"Of course it is a disappointment to have lost a replay at home but we can't afford to have a hangover. We have come back strongly in the SPL from a dip and have now gone six games without defeat to climb back up to third.
"It's vital we keep that run going at Hibs. We know that there is every chance a few of the current group of players could be leaving the club at the end of the season and if that is the case then it would be great for them to go out on the best possible league finish.
"And hopefully they can help us achieve European football again for a second consecutive season.
"So that is the challenge that I have thrown down to the lads and one that starts this weekend. All our focus is now on the SPL."
McCall is hoping that midfield play-maker Nicky Law will shake off the injury that sidelined him against the Dons on Tuesday night and return to play a key part against the Hibees.
McCall said: "It was a big blow to lose Nicky for the Dons game but he had picked up a knock against Ross County and didn't manage to shake it off. But we are hopeful he will make it back for the trip to Easter Road.
"Although Stuart Carswell did really well, Nicky's creativity would have been a big help for us in trying to unlock a very well organised Aberdeen side.
"Given how well Nicky had played against Ross County in the previous game and his superb goal against them, his absence was really unfortunate."
But there was no doubt that Tuesday's deflating cup exit at the hands of Craig Brown's men has left a strong sense of what could have have been for the manager.
He said: "We played a lot of good stuff in the first half but only really created two chances.
"After the interval I felt we would kick on but we fell away instead. That was frustrating but as I said all our focus has to be on the SPL now."