Boro, who won 1-0 at Elland Road in August, are bidding to claim their first league double over their rivals from West Yorkshire since 1962-63.
After taking two points from their last three games, United need a win to climb back into the pack chasing the play-offs – something that Mowbray believes will lead to the visitors casting caution to the wind next to the Tees.
The Boro manager said: “Leeds have been giving it their best shot all season. When a new manager comes in, it gives the team an extra impetus, a lift. I watched their game at Hull in midweek and they started very fast, very intense. We will expect the same.
“They will be here to take three points. A point or a defeat does nothing for them, so they will be coming here very positive. They have quality in the final third, with (Robert) Snodgrass, (Luciano) Becchio and (Ross) McCormack, who are all good quality individual footballers. They can hurt any team in this league.
“For us, it is a day for concentration and focus, and, while we need to be mindful of their strengths, we need to ask questions at the other end of the pitch and see if we can get a good performance, some goals and a victory.
“I expect a high-energy intense game from them, they will be coming to win.
“I don’t think they’re looking over their shoulders at the bottom half of the table. Instead, they will have a real go at the game and be as positive as possible. For them, anything other than a win doesn’t really help their cause.”
Rhys Williams returns tomorrow after suspension but Kevin Thomson (gastroenteritis) remains a doubt along with Nicky Bailey.
Last season’s visit of Leeds attracted the Riverside’s biggest attendance of the season as 23,550 came through the turnstiles despite the game being shown live on Sky.
That represented a significant rise on the club’s average of 16,377 and Mowbray is hoping for a similarly large crowd for the visit of Neil Warnock’s side.
Asked if a bumper crowd could help his side, the Boro chief said: “I am sure it will. I have seen cases of this over the season, where a bigger crowd has had an effect.
“In midweek, we had 14,700 against Barnsley as opposed to 28,000 against Hull on Boxing Day, it makes a huge difference to the teams, to the players, and it makes a difference to the spectators, too.
“They like to be involved in a football match where they are partaking, the noise and the atmosphere and the game is ebbing and flowing – it’s a better matchday experience for the fans.
“Hopefully, it is a decent crowd, and a decent game and, from our perspective, three points.”
On fourth-placed Boro’s run-in, Mowbray added: “The run-in is 12 games, we are going to need all of them. After Sunday, we have got two midweeks back-to-back, five games in a fortnight.
“We have got to go to Brighton, got to go to West Ham, back to Ipswich, to Birmingham – they are all huge games against teams in good form at the top of the table, and yet we don’t see it as a negative.”