By Will Butcher

John Hartson has revealed his surprise on Twitter after Celtic star Leigh Griffiths was omitted from the Scotland side for Tuesday’s World Cup qualifier against Slovakia.

The striker was left out of the starting XI for the away trip as manager Gordon Strachan instead opted to start Sheffield Wednesday’s Steven Fletcher up front.

Former Celtic star Hartson, who played for the Hoops between 2001 and 2006, questioned Strachan’s decision to leave out the former Wolves man on his personal Twitter account.

Griffiths has recently been struggling to return to full fitness after picking up a hamstring last month.

His route back to the Celtic side has also been hampered by the excellent form of summer signing Moussa Dembele.

Despite struggling to shift former Fulham man Dembele, Griffiths has scored eight goals in 12 league and cup appearances this season for the 47-time Scottish champions.

Celtic’s number nine, who made his debut for Scotland back in 2012 against Luxembourg, was overlooked in Strachan’s last starting 11 as they failed to beat European minnows Lithuania.

The 26-year-old was forced to remain on the bench until the 71st minute, before coming on as the Scots scored an 89th-minute equaliser.

In other Celtic news, this playmaker could be the latest player to move south after excelling in recent matches.