Hasselbaink believes football is no longer Rashford's priority.
He told Genting Casino: "When you look at Marcus Rashford and you look at his body language, and I'm not saying this is true, but it looks like football is not his main priority.
"Do we know if Rashford can play football? Yes. Hell yes. When he's playing off the left and he's playing his best football, he's a very, very good player. He’s a top player.
"When he was at his top level, he used to sprint so much and run in behind the defence. He used to work so hard running at defenders, scaring defenders.
"That’s when Marcus is at his best - and I just don't see that enough anymore. I don’t see a player that is willing to push himself like he used to, and he needs to get that back.
"He needs to get back to being a menace with and without the ball. He needs to work harder on the defensive part of the game. There is no doubt that Marcus Rashford has the ability. It’s a mental thing. It’s about unlocking his mind and mentally."