And the pundit has also discussed the way Leeds have been run by owner Massimo Cellino recently, suggesting they won't be returning to the Premier League any time soon if they are intent on producing young players only to sell them and boost the Yorkshire club's bank balance.
Lawrenson told the BBC: "Leeds are doing OK in the Championship but again are nowhere near promotion.
"They seem to be bringing some good young players through but they are selling them on. That is great for their bank balance but it is not going to get the club back in the top flight.
"There will be a lot of Leeds fans at Vicarage Road and there should be a great atmosphere but I am backing the Hornets to go through."
Sam Byram was the most prominent example of a young player being sold by United this season.
However, head coach Steve Evans has been at pains to recently point out that the likes of Charlie Taylor, Lewis Cook and Alex Mowatt are still at Leeds.
Whether they will be in the summer remains to be seen but, for now, they are fully committed to Leeds.
Leeds drew 0-0 with Middlesbrough on Monday night, while Watford won 2-1 at Crystal Palace last weekend.