Celtic defender Thomas Rogne has rubbished suggestions that his side lack mental strength after the Bhoys missed the chance to seal their first Scottish Premier League title in four years last weekend. Celtic slipped to a 3-2 loss to Rangers at Ibrox on Sunday, a week after Neil Lennon\'s side had been defeated in the League Cup final to Kilmarnock. However, with the chance to possibly wrap up the title at Celtic Park on Sunday against St Johnstone, Norwegian defender Rogne dismissed any thoughts that his side had been struck by stage-fright, pointing to their recent 26 game unbeaten run as proof of their mental strength. \"We played a lot of big games and won them. We\'ve lost two big games now, but that happens,\" said Rogne, who scored his side\'s second goal in the defeat to Rangers. \"The game we played against Rangers on 28 December was probably an even bigger one than Sunday because we had the same amount of points. And we won that. \"So we have played big games. We won the Scottish Cup final last year, which was a big game. Now we have lost two and people are talking about our mentality being bad, but I just think that\'s nonsense. \"We have strong characters in the dressing room. We were 15 points behind and somehow managed to get to 18 in front. Something has happened there. You don\'t have a weak mentality if you have managed to do that. We want to win every game. We put pressure on ourselves because we think we are good enough to do it.\" Celtic could potentially clinch the title on Sunday if Rangers slip up away to Motherwell on Saturday. And Rogne believes the defeats to Kilmarnock and Rangers will soon be forgotten once the league championship is back at Celtic Park. \"If we win the league, that\'s all that matters. Sometimes you lose games in football,\" the Norwegian said. \"We conceded a late goal in the cup final and that\'s part of the game. Against Rangers, it was a bit of a strange game and that\'s what happens really. I hope we haven\'t subconsciously switched off. I don\'t think we have. We just want to get back to winning ways and look forward again.\" Celtic will be without Cha Du-Ri, who lost his appeal against a red card shown to him at Ibrox, and midfielder Victor Wanyama through suspension. Rangers could delay Celtic\'s title celebrations for another week if they can win away to third-placed Motherwell. The Ibrox club were docked 10 points for entering administration in February and only hold a three-point lead over Stuart McCall\'s side in the race for second place. However, after a morale boosting win over their Old Firm rivals, striker Kyle Lafferty insists his side are still the best in Scotland. \"As a team, we\'re the best. We play the best football and when the going gets tough, we\'re always there and accounted for,\" the Northern Ireland international said. \"When we\'re the underdogs, we come out on top and no matter what people put in front of us, we\'re always there. \"We\'ve taken massive steps as a team and I think the manager has been superb with the way he and the coaching staff have handled things. They really showed to everyone on the outside that we\'re a team.\" Fixtures Saturday Motherwell v Rangers, Dundee United v Dunfermline, Hearts v Aberdeen, St Mirren v Kilmarnock Sunday Celtic v St Johnstone, Inverness CT v Hibernian