The 49-year-old goalkeeping coach worked with the left-back at Vitesse Arnhem until earlier this week, when the defender completed his move to Old Trafford.
"If he can play plenty of games then people will love him because he gives absolutely everything," van der Gouw told ManUtd.com. "Don't worry about that; he'll never let you down.
"He's scored a few goals, but that's because he started out as a left midfielder. He only became a left-back in the last couple of years, but he made such big progress that it became his position.
"He still likes to go forward and try to score. He has a powerful kick, a very good left foot and he puts in some good crosses, too. He has a lot of energy and he's good for team spirit."
Van der Gouw made 60 appearances in six seasons with United, and passed his experience onto his young compatriot, who is champing at the bit to make his mark at Old Trafford.
"He's so excited about joining United," said Raimond. "Having got the chance, he really wants to go for it. He was very impressed with what he saw of Old Trafford when he went to sign, even though it was empty. I know the feeling.
"I told him he was very lucky to be arriving at a club like United, because it's a totally different world to any other club, and I told him to take the chance with both hands. I really hope he does."