Martial signed for United for a record fee from Monaco.
Martial signed from Monaco for a record fee - with some reports suggesting as much as £58 million - making the 19-year-old the world's most expensive teenager.
Saha is quoted by Goal, saying: "He's got that speed, that power, he's got that youth in him so he'll surprise a lot of defenders because they don't know him.
"It's a great asset for Manchester United and that's what they needed because up front they lack speed sometimes.
"In France we call him the next Thierry Henry because he can play left or right, he's got a great ability with the ball, he can take on three, four players with ease, there is no problem. At the same time, the new generation have no fear.
"He's got such an ability that he can win trophies for Manchester United I believe that, but I don't want to put too much pressure on him."
The reported transfer fee has raised a lot of questions about Martial and whether he can handle the tag of being the world's most expensive teenager, as well as performing for a Manchester United side that is looking to kick on from last season's fourth-placed finish in a side that will be relying on him to find the net regularly given the scarce resources Louis van Gaal's side has up front.
Wayne Rooney will be the man expected to get the lion's share of the goals this season but there is still a lot of pressure on Martial to perform, and being compared to a player that had such success in the English game in Thierry Henry will mean there is likely to be a lot more scrutiny about his play. Only time will tell whether he has the tools and the quality to live up to those heights.