The big surprise to him was that it took so long for Roman Abramovich to offer Di Matteo the job after winning the Champions League last season.
Fergie said: "It's bold to play that way for a new manager. They had the confidence from winning the Champions League but he's been bold.
"You've got to give the lad credit. I think it's very positive.
"Lampard's probably coming to the end, too."