Manchester United midfielder Ander Herrera was forced off during the first half versus Watford at Vicarage Road on Saturday lunchtime, with what appeared to be a hamstring strain.
Herrera had played 24 minutes - including assisting Memphis Depay's opening goal for United, on his return to the starting line-up - before pulling up and being left incapacitated on the turf. Whilst the severity at this time is unclear, the look of frustration etched on the Spaniard's face, suggested a potential lay-off issue.
Herrera injury a concern for Van Gaal
The injury to the former Athletic Bilbao man comes less than a week after Anthony Martial sustained a foot injury. With Marouane Fellaini out with a calf strain, Louis van Gaal will be wary of any further injury absences, with crucial Champions League and Premier League fixtures on the horizon, not to mention the hectic festive period just over a month away.
Herrera, despite being in and out of the starting line-up for The Red Devils, remains United's most technically astute and direct player in their ranks and is often the driving force from attacking midfield.
Spaniard's goals and assists would be a loss
Should Herrera be forced out for any length of time, his all-round contribution to United's play will be felt. Herrera has either scored orset up 25% of United's goal, considering the side have scored just 18 in 13 games.
With games versus PSV Eindhoven and domestic high-flyers Leicester City to come in the next seven days, Herrera could be set to miss out. Should the midfielder miss any more action, though, only time will tell how widely his absence might be felt.