McCormack sustained the injury after stepping off the bench for the final 21 minutes in Scotland's goalless draw against USA at Hampden Park last Friday and will miss Tuesday's friendly in Norway.
But he is expected to be fit in time to resume for Leeds in this weekend's home game against Middlesbrough.
The 27-year-old was a late call-up into Scotland's squad after Blackburn striker Jordan Rhodes had pulled out with a sprained ankle.
Former Rangers forward Kris Boyd returns to the squad having last turned out for Scotland in a 2-1 win over Liechtenstein in 2010.
McCormack, who won his 10th cap for Scotland against the USA, was making his first appearance for his country since their home defeat to Belgium in September.
The former Motherwell and Cardiff forward has been in fine form for Leeds this season, scoring all four goals in their recent 4-2 win at Charlton to take his tally in all competitions to 12 in 20 matches.
He is currently this season's leading goalscorer in the Championship with 11.
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