The 22-year-old had a storming performance against Sir Alex Ferguson's side in Wednesday's 1-1 Champions League draw at La Beaujoire-Louis Fontenau, earning praise from all corners suggesting that he has done enough to earn a place in the French squad for the World Cup.
Despite winning Le Championnat last season, The Canaries have struggled so far this term, and only a recent run of good form has lifted them away from the relegation zone.
Landreau reportedly turned down a move to Barcelona during the summer and, although he does not regret staying to skipper the side this season, he believes he is ready to move onto a bigger stage.
"I don't regret staying for this season, it's quite honourable to be fighting for Nantes the way we are even if it is less prestigious than fighting for a title," said Landreau.
"I'm mature and I feel that I don't need an intermediary stage before joining a big club.
"I have never been so close to leaving, I've got plenty of experience and I'm still progressing. I've got more and more consistent as I've shown in Le Championnat, the Champions' League and with France Under-21s. But Nantes aren't doing very well and that's not doing me much good."
Barthez urged French coach Roger Lemerre to select Landreau for the World Cup squad after putting in performances way beyond his years.
Canaries coach Marcos has warned Landreau against signing for the first big club that comes along in the summer, and believes that he should bide his time and succeed Barthez as the number one at Old Trafford.
"If I were Mickael, I won't bother with signing for another club before leaving for Manchester," said Marcos.
"I would wait calmly in Nantes for one or two seasons, until Fabien Barthez will leave his place."
Marcos is desperate to keep hold of his captain for another couple of seasons, but with the performances he keeps putting in, the lure of one of the top names in Italy, France or England could lure him away at the end of the season.
