MIDDLESBROUGH will have to be in top gear to beat Oxford United, according to manager Aitor Karanka.

The Premier League side are odds-on to progress to the Emirates FA Cup quarter-finals against their Sky Bet League One underdogs.

But Boro only scraped past League Two side Accrington Stanley at the Riverside in the previous round and Karanka is wary of a U’s side who beat Newcastle United 3-0 to reach the last 16.

The former Real Madrid centre back said: “When you analyse them you feel it wasn’t a coincidence they beat Newcastle 3-0, they have players who scored good goals, play good counter attacks and a young Spanish player (Toni Martinez) up front who I know.

“We experienced in the last round how hard you can make it if you go to the pitch thinking it will be easy.

“It’s going to be a tough game, especially if we don’t go to the pitch with the right attitude.”

He added: “Our players are intelligent and know this is a good opportunity to go through, but to reach the next round we have to be at our best.”

Karanka insisted Middlesbrough will field a strong XI, although he hinted at changes.

He said: “I will put my strongest team but I have to think I have 25 players, we have another three months in front of us and all of them will be important.

“I want to win the game and trust every player in this squad.”