United's mixed season so far has attracted plenty of criticism.
Indeed, United were knocked out of the Champions League earlier this week and have endured a slow start to their Premier League season - even though they are most certainly in title contention based on current standings.
And the pundit feels not one Manchester United player can truly be considered a success except for Smalling or De Gea, at a push.
Redknapp told Sky Sports: "There aren't too many of their players - if any - who you would say have had a really good season so far. Chris Smalling and David de Gea have done well but that's about it.
"As for Van Gaal, the jury is still out on his work at Manchester United, for me."
There has naturally been plenty of criticism aimed at Van Gaal's style of play at United. Fans don't seem satisfied and even those who value substance over style recognise the fact this team doesn't ever seem to attack or score goals.
But, considering Redknapp's comments, another key criticism is the amount of money the Dutchman has spent at Manchester United.
Players have been bought and sold en masse but is the current United side any better than the one Van Gaal inherited?
It's telling that the two players Redknapp has mentioned were at Old Trafford before the manager himself...