Newcastle United winger Matt Ritchie has pulled out of Scotland's squad for their World Cup qualifiers against Slovakia and Slovenia.
The 28-year-old played the full 90 minutes of the Magpies' 1-1 draw with Liverpool on Sunday afternoon and was awarded the sponsors' Man of the Match accolade.
Shortly after the match, however, Ritchie withdrew from Gordon Strachan's squad for the crucial games, beginning with the visit of Slovakia on Thursday evening.
Strachan has called McGregor up in his place, with the Celtic ace surprisingly being overlooked for selection once again earlier this week.
McGregor scored twice in the Hoops' 2-2 draw with Hibernian on Saturday afternoon, taking his tally to six in 15 appearances this term.
Celtic duo Scott Brown and Stuart Armstrong will also play no part in next week's fixtures, which Scotland need to win to be in with a shot of claiming a qualification playoff spot.