Only Celtic can stop Celtic winning the treble, says ex-keeper Gordon Marshall Published on Tuesday 13 March 2012 01:01 GORDON MARSHALL believes the only remaining threat to Celtic winning the treble this season comes from within Neil Lennon's team. The SPL champions-elect can secure the first leg of the domestic triple crown this Sunday when they face Kilmarnock at Hampden in the Scottish Communities League Cup final. Marshall, who experienced the pain of final defeat in the tournament with both clubs during his playing career, feels Kilmarnock's only hope of causing an upset lies with Celtic failing to apply themselves properly. "I can't see anyone stopping Celtic now," said the former Scotland international goalkeeper. They are the best team in the country at the moment. The only thing Celtic need to watch our for is Celtic, if they don't go in with the right attitude, which I doubt. They have a manager who has been in that position before and knows what it's all about. They will be well prepared. Preparation for big games becomes second nature to them. For the Kilmarnock boys it's a wee bit harder trying to control things. There are people wanting tickets, lots of distractions in the background. They are trying to keep things nice and low key but it doesn't happen. It's a massive day out for the staff and supporters. The players will play their part, but I think they will need Celtic to be off it to give them any chance. Killie will enjoy playing on the big pitch at Hampden, the way their manager Kenny Shiels talks about. There will be a lot more room to pass the ball about. But they will need to score first and have something to hold on to. Celtic become too strong if they take the lead and they haven't been losing too many goals either. Marshall is well aware that underdogs do have their day in League Cup finals, having been on the wrong side of a shock in 1994 when Raith Rovers defeated Celtic on penalties at Ibrox. But seven years later, there was a more predictable outcome when he was in the Kilmarnock side beaten 3-0 by a Celtic side en route to the club's most recent treble. Now goalkeeping coach at Motherwell, for whom he made his last League Cup final appearance in 2005 when they lost 5-1 to Rangers, the 47-year-old cannot recall the tournament with any fondness. "I played three, lost three and don't have good memories of them," he added. The first one with Celtic against Raith certainly wasn't very good. I should have saved Raith's second goal during the match and I should have saved about three of the penalties in the shoot-out as well. That was disappointing. Then when I moved to Kilmarnock, we had a good team and got to the final in 2001. We came up against a good Celtic side which Martin O'Neill was building. He had some big players and they also had the most ruthless striker I've ever played against in Henrik Larsson. But although he claimed a hat-trick that day, it wasn't. The second goal took so much of a deflection, I'd maintain it was an own goal. That might be harsh on Chris Innes, who it hit, but I would still argue whether it was a hat-trick. It was 0-0 at half-time and we actually started the game really well. I remember Ian Durrant played. There was a lot of worry and concern over whether he would make the final. He was keen to make it but there were a lot of problems with his knee. I think he wanted to go out in a wee blaze of glory. The game seemed to go for him at the start, he played extremely well. But after around 30 minutes, that was it. His knee packed in and it was the last game he played. I wouldn't say we lost our way after he went off, but our luck maybe ran out. The biggest thing when you play against Celtic is that if you give them opportunities, they take them. We gave them too many opportunities. If you do that, they can steamroller you. Marshall has cast a critical eye over both of the goalkeepers who will be on duty at Hampden this weekend and is impressed by the progress made by Celtic's Fraser Forster and Cammy Bell of Kilmarnock. "Forster was actually mentioned as a possible target for Hibs when I was goalkeeping coach there," revealed Marshall. He had been identified by the scouting system there when he was 18. When he first came to Celtic, he looked very stiff, rigid and unorthodox. But through working with goalkeeping coach Stevie Woods, he has improved a lot. The mistakes have become fewer and the big saves more regular. I think he's got time on his side to be part of the England set-up. Certainly, they seem to be crying out for top goalkeepers down there at the moment. Cammy has been unfortunate with injuries at times in his career but it looks like he is over that. I worked with him when he was just a young lad at Killie and he showed a fair bit of determination to come through to become the "keeper he is now. He's been in the Scotland squad and hopefully has a bright future ahead of him. I certainly think he is going to be the busier of the two goalkeepers on Sunday and he'll need to be at his best for Kilmarnock to win the cup.