Roberto Di Matteo is to be confirmed as the new manager of West Bromwich Albion tomorrow. The Milton Keynes Dons manager succeeds Tony Mowbray, who has moved to Celtic.

Alan Irvine, the Preston North End manager, had been the favourite but Di Matteo impressed at a interview with jeremy Peace, the made himself the West Brom board's choice with an impressive interview. Dave Jones, the Cardiff City manager, was also linked with the job, but preferred to stay with the Welsh club.

Compensation is believed to have been agreed with MK Dons, with a formal unveiling expected tomorrow after personal terms have been agreed. Eddie Newton, Di Matteo's assistant at stadiummk and a former team-mate at Chelsea, is expected to join him at The Hawthorns.

Taking over a team that was in the Barclays Premier League last season and will be among the favourites to return marks a remarkable ascent for Di Matteo, 39, who will be in only his second season as a manager. In his first, he led MK Dons to within two points of automatic promotion to the Coca-Cola Championships. The Dons had to settle for the League One play-offs, where they were beaten on penalties by Scunthorpe United in the semi-finals.

Yet his appointment as successor to Paul Ince was a risk for MK Dons and unexpected even to Di Matteo. “It was the first time I’d even considered, let alone applied for, a manager’s job," he said. "I went out of courtesy, partially because I thought the interview would be a great experience. I turned up, I was myself as I always am, because I know I’m not a good actor, and I thought nothing would come of it.”

He had signed a contract extension in December designed to keep him at the club June 2011.

The Italian had a distinguished playing career, winning 34 international caps and enjoying success in this country with Chelsea, winning two FA Cups - scoring in each final - a League Cup and a European Cup Winners’ Cup. He retired as a player in 2002, his career effectively ended 18 months earlier when he sustained a triple leg fracture sustained in a UEFA Cup tie against FC St Gallen of Switzerland

The departure leaves MK Dons looking for a new manager for the fourth successive summer after Ince left to manage Blackburn Rovers last June. Martin Allen departed for Leicester City in May 2007 and Danny Wilson left in June 2006. For Pete Winkelman, the club's ambitious chairman, the fact that his choices prove their worth and are sought after by other clubs proves his judgment of potential - but must make him wonder why the men he selects do not see his club as a place they can achieve their long-term ambitions.