Pep Guardiola agrees Erling Haaland is on a trajectory that could reach the levels of Cristiano Ronaldo and Lionel Messi but believes only time will tell if his player will be counted among the greatest to ever play the game.The Manchester City striker moved within touching distance of the Premier League single-season scoring record, 34, jointly held by Alan Shearer and Andy Cole after bagging a brace in his side’s 4-1 victory over Southampton.Haaland has now netted 30 in England's top flight, with nine games left to equal or beat the record.