NEW YORK -- Chicago Bulls coach Tom Thibodeau's worst fears were realized as he watched his team get outworked on the boards during Monday night's 110-91 loss to the Brooklyn Nets on Monday night in Game 5 of the Eastern Conference semifinals.

Instead of playing like a team that was fighting for its playoff life, the Bulls played like a team that knew it had a cushion. The Bulls got away from the hard-nosed attack they've shown throughout the season and replaced it with an inconsistent effort that made the veteran coach furious at several points.

"I feel like we made a lot of mental mistakes," Bulls swingman Jimmy Butler said. "We didn't get to all the loose balls, we didn't rebound, we didn't execute and on the defensive end we just made mistakes that we normally don't make because we got away from ourselves. It's very correctable. We know what we have to do for the next game."

The attitude is admirable, especially considering the Bulls were playing without defensive leader, and captain, Kirk Hinrich, but why in the biggest game of the season to date did the Bulls decide to play differently? The mental approach that has been so sharp for the Bulls went missing at the wrong time.

"We got a lot of banged-up guys but it's still frustrating to know that you had a chance to close it out tonight," Bulls forward Taj Gibson said. "When you look at it, we really played like a team that was really comfortable with just being (up) 3-1, instead of just putting our foot on their neck and winning the game. We just got to watch some film and regroup and grind on the next one."

The Bulls stopped grinding too many times in this game and they knew it. Now they face the reality of knowing that the pressure will be on them to close out this series in Chicago. The last thing the Bulls want is for the Nets to pull out a win at the United Center and have all the momentum coming back home for Game 7 against a team that is playing through a myriad of injuries. The hard work the Bulls have dumped into this series, and this season, will be for naught if they can't find a way to close things down now. The Bulls' locker room had an upbeat vibe after Monday's game but the team knows the challenge still in front of them.

"There's always pressure but we love that," Bulls forward Carlos Boozer said. "That's why we're athletes, that's why we compete and we look forward to it. I think going home will be great for us. Obviously we wanted to close it out but we didn't. So you look ahead, you can't keep looking backwards, we're looking ahead to the next game. Watch the film, make our corrections, and we'll be ready for Game 6."

Veteran center Nazr Mohammed echoed those sentiments. Having spent more than a decade and a half in the league, he wants his young teammates to focus on the game plan, not the fact that a home loss would wreck this tough team's confidence.

"(The media) would think it's more pressure and the average fan at home would think it's more pressure but it's (a) close-out game in general," Mohammed said. "There's pressure on you to close it out. When you're up 3-1 there's always pressure on you to close it out, but I don't look at it as pressure. I look at it as you have a goal, you want to accomplish it, there's someone in the way of your goal so you have to be focused and go out there and you have to take the game and you're not going to expect them to give you the game, because they want it, too."

No matter how the Bulls try to spin it, they know that the focus is now on them to shut things down at the United Center. The Nets know it, too.

"I think we put the pressure on them now," Nets forward Gerald Wallace said during his on-court interview with the YES Network. "I think they were expecting to go back to Chicago. I think they feel more comfortable playing in Chicago. We just have to go in, play our 48-minute game, and steal one in Chicago."

The Bulls are focused on doing the same thing. They know they didn't play their game Monday. They know they gave up 17 offensive rebounds and weren't as aggressive as they had to be on either end. Most of all, they knew they had a chance to shut things down but instead they gave the Nets the lifeline they were searching for. Now the Bulls have to find their own to take it back for good.

"We just got to play, regardless of whoever the pressure's on," Bulls guard Nate Robinson said. "Quite frankly, I don't care who the pressure's on. We just got to go out there and play our game and have fun and play hard and continue to get better. … It's a must win for us. We've got to continue to play hard and give our fans that win that they deserve."