Heidar Helguson is undergoing an MRI scan to determine the extent of the calf injury he sustained on Saturday.

The Iceland striker is a doubt for this weekend's trip to Reading after leaving Vicarage Road on crutches following the dramatic 3-3 draw with Leicester.

Boss manager Malky Mackay told the Watford Observer: "We are going to have Heidar scanned to find out what sort of damage there is.

"We are working extensively with him to try to get him ready for the weekend but we will know further after his scan."