Manchester United had a scout posted to Espanyol's 1-0 wn over Alaves on Sunday.

El Mundo Deportivo says United scout Toni Lima was there to run the rule over defensive duo Aaron Martin and David Lopez.

Lopez, 27, is a versatile defensive player, operating at centre-back but also as a defensive midfielder. He has a £34million release clause which United could comfortably match.

Martin operates primarily as a left-back - a position which Mourinho is expected to strengthen in the summer following his heavy criticism of Luke Shaw.

The 19-year-old has made 25 appearances for Espanyol this season in all competitions and is said to have a £25m release clause.