The Gunners head into the game on the back of their thumping 4-0 replay win over Hull in midweek as they bid to win the competition for the third straight year.
Arsenal came from a goal down to earn a 2-2 draw against Tottenham in last weekend’s north London derby clash in the Premier League.
And former Liverpool man Lawrenson is expecting to see Arsene Wenger’s men beat the Hornets and reach the semi-finals at Wembley.
Writing in his column for BBC Sport, Lawrenson said: “Arsenal were slightly flattered by the 4-0 scoreline in their fifth-round replay win at Hull on Tuesday.
“The Gunners also have a few injury problems to deal with and they will be up against a Watford side that are just going to go for it in this tie.
“Watford played well in an open game against Leicester last weekend but were beaten by a quality goal, and they will not go down without a fight at Emirates Stadium.
“This has become a big competition for Arsenal boss Arsene Wenger, again.
“He has been getting some stick from a few fans and he probably needs to win the FA Cup for a third straight year just to shut some of them up.”
FA Cup holders Arsenal will then turn their attentions towards their Champions League last-16 second leg clash at Barcelona on Wednesday night.
The Gunners are currently third in the Premier League and eight points adrift of leaders Leicester with nine games left to play this season.
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