The 26-year-old left Athletic Bilbao for Old Trafford last summer and enjoyed a relatively successful debut season at the club, netting eight goals in all competitions, but has found his first team spot under threat this term.
The arrivals of Bastian Schweinsteiger and Morgan Schneiderlin have meant that Herrera has started just one of Man United’s opening four Premier League fixtures and even then the cultured playmaker was subbed.
Manchester United FC news.
Manchester United ‘dull and functional’ under Louis van Gaal, says Premier League legend
Why David de Gea will almost certainly sign a new Manchester United contract despite Real Madrid link
A move back to La Liga may tempt Herrera, especially if by the time the January transfer window opens he is still playing second fiddle and warming the bench.