Lampard was omitted from Roy Hodgson's starting line-up in England's 2-0 win over Poland at Wembley last week, with Manchester United's Michael Carrick preferred instead.
There have been some suggestions Hodgson may face a tough decision over the central midfield position behind captain Steven Gerrard, which could see Lampard overlooked for the World Cup Finals.
But Petit believes, at 35, he is still up to the challenge.
"Of course he doesn't have the same skills physically but. It doesn't matter because he's got so many young players around him now to do the same stuff he has to do," the former French international explained.
"He's very gifted very talented he wants to win everything. So when I look at him with the national team, I'm not questioning his physical skills if he can cope with the demands and the World Cup.
"He's a great player, he's made Chelsea history, so he will try with the team, on and on, weeks on weeks. For me, I'm not worried about Frank," he said.
Petit added England may not win the competition next summer in Brazil, but expects they could be world champions in the not-too-distant future.
He recalled: "Before we were world and European champions we went to the semi-final here in England in Euro 1996 - but before that it was a long, dark way."
Hodgson and former England captain Rio Ferdinand have now joined the Football Association's (FA) commission which will look in to the state of the game in England.
FA chairman Greg Dyke, hopes the group will deliver its report around March next year, but Petit agrees with recent comments from Louis Saha and Edwin van der Sar that the simplest solution could be for English players to look abroad to improve their abilities.
"With all the players who were playing in France [in the mid 1990s], I'm not sure we would have won the 1998 World Cup. But two, three or four years before that, most of the players went abroad," he said.
"We learnt about international demands at the highest level, we worked as well with the pressure we received on a daily basis, then we brought them back to the national team with more confidence and belief in ourselves.
"In France, football was a job it wasn't a religion, it wasn't a sport and the main difference is that we got the confidence to win the World Cup abroad," he said.