Club managers around the world will be waiting to see whether their players return unscathed and there are question marks over at least two of our men ahead of the trip to Vicarage Road.

Jose Mourinho could be without Luke Shaw, who sustained a head injury in England's UEFA Nations League match against Spain at the weekend. Some reports suggest the left-back will be obliged to serve a mandatory seven-day concussion period of absence, though this has not been confirmed.

Shaw has enjoyed a bright start to the season for United, picking up the Goal of the Month and Player of the Month awards for his performances in August, and will be assessed by United's medical staff before any decisions are taken. After the trip to Watford, the Reds' next fixture is away to Swiss side Young Boys in the Champions League on Wednesday.