It was Sam Allardyce that brought the Oman international to Wanderers from Lyn Oslo in January 2006.
However, he only made a handful of appearances for the club before joining the Latics on loan in the summer of 2010.
Al-Habsi impressed in his first season at the DW Stadium, helping the Lancashire club stay up on the final day of the season and collecting their Player of the Year award.
He then made a permanent £4million switch to the Latics in the summer of 2011, a move sanctioned by then Bolton boss Coyle.
The 46-year-old admits he was reluctant to let the player go, but felt it was the best move for all concerned.
"I never wanted to sell Ali, as was well-documented at the time," he told the Wigan Evening Post. "But we needed to raise revenue to try to bring in an attacking player, and we had three outstanding goalkeepers at the football club.
"I looked at it from a player's point of view, and thought that he needed to play football. Wigan came in with the loan move, he did very well, and it was only natural then that they did the deal to keep him. It was a good deal for everybody - a win, win, win situation.
"Having Ali here will be a great asset to me, because he is an outstanding man as well as an outstanding goalkeeper. It'll be nice to link up with him again and he'll be a key man for us."