The 34-year-old joined the club on a free transfer from Real Madrid last summer.
“He is out there leading by example,” Allardyce told the Daily Star.
“Our young lads are playing well for us but Michel is doing more than his bit and his experience has proved invaluable.
“He has come to terms with what it takes to play in the Premier League and, since December, has been outstanding for us. There is not a fitter lad about, that’s what I like about him.”
