Manchester United defender Marcos Rojo has admitted that it is difficult to keep cool during derby games.
United are preparing to face Manchester City at the Etihad Stadium on Sunday, and the Argentina defender stressed the need to avoid "a silly red card" on his 26th birthday.
The Red Devils could cut the gap to fourth-placed City to a single point if they take the derby spoils, but defeat will all but end their hopes of playing in the Champions League next season.
The pressure on United manager Louis van Gaal has grown in the buildup to this match following the club's Europa League exit at the hands of Liverpool on Thursday. Van Gaal admitted after the game that his injury-hit squad had failed to live up to expectations this season.
Rojo said that he has been tired recently, having undergone shoulder surgery and been ill, but is "getting better." He had not played for three months until returning to the side on Feb. 25, but has slowly recovered match fitness -- and played a full 90 minutes for the first time since his comeback when United lost 1-0 at West Bromwich Albion a fortnight ago.
Speaking to MUTV, Rojo said: "I always try to be quite relaxed before these games. The way I see it is if you go into this kind of game overly pumped up, you can get yourself into trouble -- you have to try and keep calm.
"There's no point being fired up and getting a silly red card as that doesn't help the team. You have to keep your head all the way through and do everything you can to win."
When asked if it is easy to stay calm, he replied: "No, especially in games like these that usually have a great atmosphere. You have to give 100 percent though and stay as calm as possible. When you walk out on that pitch, you have to have the fire in your belly but keep a cool head at the same time.
"I've seen that people are passionate about derbies and that they mean an awful lot to the people of Manchester. City have grown a lot recently and United have the history and now it's a really well-contested derby."
Van Gaal bemoaned the lack of preparation time for the game at the Etihad Stadium, which comes three days after the exit to Liverpool. That failure to progress in the Europa League meant that finishing in the top four is the only way United can qualify for next season's Champions League.
Rojo, though, said that the 3-1 aggregate defeat to Liverpool can increase unity in the camp ahead of the derby. He said: "We need to move forward and try to get out of the bad run that we're in. We're all very much together as a team and are desperate to move the club forward for ourselves and for the fans who are always right behind us.
"Every day I'm getting better. I'm a bit tired right now as I've been ill recently and, when you play games like these, you leave everything out there on the pitch. The manager knows this and asked me to give as much as I could in recent matches. It's difficult when you've been out for the best part of three months to come back and hit the ground running, but I'm getting stronger with every game now."