However, West Brom are overly reliant on Salomon Rondon in the final third and their manager is surely keen to reinforce this summer.
Younes Kaboul will miss out due to a hamstring injury and the former Tottenham man is expected to be replaced by Sebastian Prodl.
Meanwhile, Watford have lost 10 of their 14 Premier League games against teams now in the top half (W3 D1) and haven't kept a clean sheet in any of those games.
Christian Kabasele and Ben Watson are not yet fit to return, while Mauro Zarate and Roberto Pereyra are long-term absentees.
The Baggies won the reverse of this fixture 3-1, last completing the league double over Watford in the 2003-04 Championship campaign. He has scored 105 goals for the Hornets and has netted nine times for them this season, including five in his last eight games.
Pulis added: "It will be a different game than the last two we've played but that's what the Premier League is about, coming up against different systems and different strengths". They have many points in the league this season and we must do our best to face them.
Reports linking West Brom with a move for Watford captain Troy Deeney are unlikely to die down after some choice words from Baggies boss Tony Pulis this afternoon. Ten weeks from the end of the season I am not thinking about that [transfers].
"I might well decide who is going to play on Tuesday after the last session on Tuesday morning".
Sky Bet have priced Watford up as the 7/5 favourites to win at home to West Brom on Tuesday night. The draw is an 11/5 chance.
Fletcher has played in every one of West Brom's Premier League matches since joining and Pulis believes there is still plenty of miles left on the clock, admitting he has been blown away by his fitness levels given his battle with ulcerative colitis, the chronic bowel disease, between 2011 and 2013.
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