The 19-year-old was a David Moyes target who was presented to Van Gaal and he approved his purchase being a move could be completed.
However, Meulensteen feels the arrival of Marcos Rojo is bad news for Shaw and is worried he could be detrimental to his progress at Old Trafford.
Asked if he believes that Van Gaal does not rate 19-year-old Shaw, Meulensteen told talkSPORT:
“Yes. It’s a big surprise for me,” Meulensteen told talkSPORT when asked about whether Van Gaal doesn’t rate Shaw.
“He would have been informed by the club that they were putting this bid in for Shaw because he’s an up-and-coming player.
“He’s got a good left foot and a lot of pace. He’s got a lot to learn to get to a Man United level though.
“He’s a great prospect but he’s brought [Marcos] Rojo in, which is bad news for Shaw.”
Meulensteen’s comments are in stark contrast to Jonny Evans who hailed Shaw as a player who will be the world’s best left-back after playing with him in pre-season.
At 19, Shaw is nowhere near the finished product but what he showed at Southampton was a fantastic level of consistency for somebody so young, so the potential is certainly there.
If Van Gaal really didn’t think Shaw was the real deal, he would not have given the go ahead to sign him.
He’s had an unlucky start to his United career with injuries but is in line to make his competitive debut against West Ham at Old Trafford this weekend, so United fans are eager to see what he can do.