The Hornets will arrive at the Riverside Stadium on Saturday trailing fourth-placed Boro by seven points and two positions with a game in hand.
Mowbray told the club's official website, www.mfc.co.uk: "They are going to be a threat. I studied them this week and they can score goals and are very hard to break down.
"They have won six away games, including big victories at Leeds, Sheffield Wednesday and Brighton, and they have some clever, creative players.
"Some people might argue it's more important not to lose to a team just behind us, but I think it's important to try to win.
"It would be a huge victory for us that would really keep them at arm's length and establish a real gap."