Leigh Griffiths insists Celtic need to be wary of lightning striking twice after the Ladbrokes Premiership leaders were drawn at home to Greenock Morton in the quarter-finals of the William Hill Scottish Cup.

The draw at Hampden Park, which had to be re-run after one of the plastic balls opened after the Hoops had been paired with Dundee United at Tannadice, saw the Championship side set for a return to Parkhead, the scene of a famous and unlikely League Cup win in September, 2013.

Dougie Imrie's penalty in extra-time shocked the home side and Griffiths believes the current Celtic team need to be on their guard.

The 29-goal striker said: "The last time they played us at Parkhead they beat us so we need to be wary of that.

"The players like Scott Brown, Charlie Mulgrew, James Forrest, who were involved in that squad just before I signed will be telling everybody else that regardless of the opposition we need to take care of them professionally."