Everton meet United on Saturday in the Premier League at Goodison Park.
"He's performed admirably for his club and country for such a long time and he seems to get better and stay at a very high level," Howard told Sky Sports News.
"That's not easy to do in that position and at a club like Manchester United.
"Hats have to go off to him and other keepers like him at that age to keep plugging away.
"I'm nine years away from that and it's difficult now because of the pressures and the work that you put in, so when you get to that age, he's done very well."