Wigan Athletic boss Roberto Martinez why he held back Shaun Maloney for so long.
Maloney hit the winner against Manchester United last week.
"There is a really strong adaptation period for certain players when they leave the Scottish Premier League and come to England," said Martinez of the ex-Celtic man.
"We worked really hard with him physically to reach the level we needed, then he had to find a partnership and position with our players. 'That takes time.
"Maybe you can move from Celtic to the Premier League. But not from Celtic to Wigan.
"With a club fighting for the title in Scotland you get a lot of possession and the main concentration is what to do with it. It is straightforward.
"In the Premier League physically, you need to find the right level, then you have to work out what you are doing off the ball and how you are going to defend. It is not easy."