Scotland will be without midfielder Matt Ritchie for the crunch double header against Slovakia and Slovenia this week.

The national side will take on their final two 2018 World Cup qualifying matches in a bid to reach the play-offs in November when they face Slovakia at home on Thursday and Slovenia away on Sunday.

Ritchie withdrew from Gordon Strachan's squad on Sunday evening, however, after playing the full 90 minutes in Newcastle's 1-1 English Premier League draw with Liverpool.

It came just hours after Celtic's Callum McGregor was handed a long-anticipated call up for the first time in three years.

The midfielder was drafted into the squad following injuries to Scott Brown and Stuart Armstrong who were both forced to drop out last week.

Former under-21 captain McGregor is still to make his senior debut having failed to win a call-up since September 2014.

He scored another two goals for Celtic on Saturday in the 2-2 draw with Hibernian, taking him to six for the season and making him the club's top scorer so far.