Big Jack claims Keane is past his best

The Parkhead club pulled off a remarkable signing coup to capture Keane in face of interest from several Barclays Premiership clubs and Spanish giants Real Madrid.

But Charlton claims the Bank of Scotland Premier League is now the right level of football for the Old Trafford legend.

He said: "I think he has made the right decision as the SPL will not be so demanding as the English Premiership or a move to Real Madrid."

The Geordie, who handed Keane his Irish debut in 1992, added: "Let's be honest, Roy is past his best, though he still has a huge amount to offer in his new 18-month contract under Gordon Strachan. It won't be as hectic playing club games in Scotland and Roy will find it easier to push forward from midfield."