The Red Devils have left themselves with an uphill task of the second leg of their last-16 Europa League tie after losing 2-0 in the first leg at Anfield on Thursday.
Scholes was highly critical of United’s display, labelling it ‘shambolic’.
But one thing he found most surprising was that Mata was given the task of captaining the side.
“That is exactly what I said: how is Juan Mata captain?,” Scholes told the Daily Mail.
“He's a good player and he's had a good month. But to be captain of Manchester United?
“I don't think there are many real leaders in there. Chris Smalling? The goalkeeper?
Manchester United v West Ham - FA Cup match preview
“They, possibly, could be captain but are they real Manchester United captains?”
United will be hoping to bounce back when they host West Ham in their FA Cup sixth round tie tomorrow (4pm).