Rovers forward Niall Ennis will be out for a couple of weeks after picking up a knee injury in the defeat against Hull City.

Ennis made a positive impact off the bench against the Tigers and was involved in Sam Gallagher’s goal.

The forward had been building up his sharpness since joining on a free transfer from Plymouth Argyle over the summer, scoring 14 goals as the Pilgrims clinched the League One title last term.

“I feel sorry for the boy because I think he had shown some good progress and some good football. He was almost getting into shape and now it is a setback,” said Jon Dahl Tomasson.

Sam Gallagher has only trained a couple of days this week after becoming a father and might not be ready to start at Watford.

“Sam played an excellent game when he came off the bench against Hull and scored a beautiful goal,” Tomasson added.

“He was really important in that game, but he hasn’t trained a lot this week. He had great news, he became a dad.

“But of course, when you haven’t trained a lot, we are a bit stretched and maybe can’t take the risk. We will see.”

Callum Brittain is expected to slot in at left-back again, with Harry Pickering suspended following his ending off against Hull and Jake Batty still out injured.

Iceland international Arnor Sigurdsson has continued to make progress in his recovery and hopes to be back in a couple of weeks.

Jack Vale also remains sidelined, but Leo Wahlstedt has been back in training after missing last weekend’s fixture through illness.

“We have very good players, but there are also some very young ones,” the boss stated. “We all know how tough this league is, but I am really looking forward to this week.

“It is going to be a challenging week – three away games in six days and a lot of travelling with this young squad.

“Ryan Hedges, he is almost grandpa to the squad at 28 years of age! I don’t think there are any other teams in the Championship or Premier League who don’t have a player over 29.

“But I am looking forward to the game, Watford are a good side and they have some quality players. Hopefully, we can play some good football against them.”