Following on from Tuesday's 1-0 win over Huddersfield Town there are players carrying knocks but they'll be checked before the trip south.
"We'll assess a couple in the morning," said Bowyer on Thursday. "We've one or two knocks but hopefully they should be fine.
"It has been a massive squad effort, you look at the contribution Josh Morris has made recently, Markus Olsson comes back in and is magnificent.
"Gael Givet plays his first game, David Goodwillie came on and ran his socks off.
"So it is going to take a big effort from everyone in the squad for the remainder of the campaign."
Bowyer has been given a boost with the news that Bradley Orr and David Bentley could come into contention after returning to training.
Orr hasn't featured for Rovers since damaging ribs in the FA Cup tie with Millwall, whilst a troublesome knee injury had sidelined Bentley.
"Both of them are back and I am delighted with that," added the Rovers boss.
"Brad is another warrior that has got a great character and he is determined to come back into the squad and help out.
"David Bentley has trained with us this week so the timing of those coming back is great for us."
Martin Olsson isn't quite yet ready to join up with group as he bids to return from an ankle injury, but he should be back before the season's end.
"He's coming back, I spoke to him this morning and he is hopeful of featuring soon," added Bowyer.
Tickets for the Watford game go off sale at Ewood at 4pm on Friday, however they will be on sale from Vicarage Road on the day of the game. Prices are £26 Adults, £15 Seniors/Students and £10 Juniors.