Aston Villa new boy Stilian Petrov has admitted that he had run out of desire to play in the SPL before he decided to leave Celtic and head for England.
The 27-year-old Bulgaria skipper could eventually cost Villa £8million, having finally secured a switch just hours before the transfer window shut last Thursday.
He told the Scottish Sunday Mail: "It all started during a game against Inverness at the end of March.
"It was early in the match and I felt no motivation, no drive inside my body to play football.
"It had never happened to me before and I tried to play on, but there was no power in my legs and my brain had switched off.
"I signalled to the bench I had a problem and told them to put someone on in my place who could help the team win. I wanted to play but felt unable to make a positive contribution.
"No matter what angle I looked at it from, only one answer kept coming back and that was I had no desire left to play in Scotland.
"I didn't want to leave Celtic, but I had nothing left for the domestic game."