Following a four-month lay-off with a foot injury in the first half of the season, Foster returned to action just before Christmas, and is again Albion's first choice.
Mel, however, has been highly impressed with Foster since taking over at The Hawthorns last month.
"For me, Ben Foster is the best goalkeeper in England," said Mel.
"In particular, he is very good with crosses. He has no problem dealing with them.
"For me, he should be England's number one at the World Cup, but Hart at City is a good goalkeeper, a good player.
"Obviously it's normal I say this about Ben because he is my player, but he is a very, very good goalkeeper."
Mel, meanwhile, is to hand 'forgotten man' Craig Dawson a new lease of life as the centre-back is to start Saturday's Barclays Premier League clash at Crystal Palace.
Dawson fell out of favour with former manager Steve Clarke as the 23-year-old was loaned out to Bolton for the second half of last season and was poised to be made available for loan again approaching the January transfer window.
But Clarke's departure and Mel's arrival have resulted in Dawson's slate being wiped clean.
With Jonas Olsson out injured, Mel has confirmed Dawson will start only his third league game for the Baggies in the past 21 months, partnering Gareth McAuley in the centre of defence.
"He is the future of West Brom," said Mel.
"He is a very good centre back, and he wants to play matches, which is normal.
"Now, it's better he stays here. For example, against Palace, we need him to play.
"Dawson is in the 11 for this game. He is ready, he wants to play, which is very good for us.
"He is Premier League quality, a strong centre back, and his mentality is very good."
- Sports & Recreation
- Craig Dawson
- Ben Foster