CHICAGO -- The Chicago Blackhawks already had an uphill climb ahead of them being down 2-0 to the St. Louis Blues in their first-round playoff series, but the adversity facing them became even greater Sunday.

The Blackhawks found out they'll be without defenseman Brent Seabrook for the next three games after he was suspended by the league for his hit on the Blues’ David Backes in Game 2 on Saturday. Chicago will now have to win at least twice without Seabrook in the lineup to keep its season alive.

Seabrook's absence leaves a large void for the Blackhawks. He's one of their top-four defensemen and has been a staple in the team's defense for the past nine seasons. He plays key minutes for Chicago at even strength and on both sides of special teams.

Seabrook was second on the team with 22:16 of average ice time during the regular season. He also had seven goals, 34 assists and a plus-23 rating in 82 regular-season games. He leads the team with four points, which includes two goals and two assists, against the Blues in the playoffs.

Blackhawks coach Joel Quenneville spoke to the media Sunday before Seabrook's suspension was revealed. Quenneville wasn't sure what would happen to Seabrook, but he knew Seabrook was important to the team.

"You need his size," Quenneville said. "You need his presence, experience and leadership. He's got the big shot on the point, and he's on our power play as well, kills penalties. So he plays all important minutes, and him and [Duncan Keith] make a real good pair for us. He's been a great pro for us."

Blackhawks defenseman Michal Rozsival was hopeful they wouldn't be without Seabrook, but he thought the team had to be prepared either way.

"He's definitely the guy that the coaches and everybody is counting on in the big, important situations," Rozsival said. "He's a big part of the club, but whatever is going to happen is going to happen. You can't control it right now. You just have to deal with it. At the end of the day, we have to win the hockey game."

Defenseman Sheldon Brookbank probably will replace Seabrook in the lineup. Brookbank often rotated in and out of the lineup throughout the regular season. He had two goals, five assists and a plus-2 rating in 48 games. He averaged 12:53 of ice time.

Brookbank does have some experience being put into difficult situations. He was inserted into the Blackhawks' lineup during the playoffs last season when Keith was suspended for Game 4 of the Western Conference finals against the Los Angeles Kings. The Blackhawks won the game 3-2. It was the only playoff game Brookbank played in last season.

Brookbank said in early April he hoped to get a chance to play in this season's playoffs.

"I live for the playoffs," Brookbank said. "I love the intensity and stuff like that. That's something I live for. That's my first and foremost goal for me personally is to get out there for the playoffs."

Rozsival and Nick Leddy may also play larger roles with Seabrook out. Leddy has averaged 17:58 of ice time in the first two games of the series, and Rozsival has averaged 17:55.

Defenseman Johnny Oduya was confident Sunday the Blackhawks could get by if they had to play without Seabrook.

"We have [Brookbank], who's been great the times he's played this year," Oduya said. "Obviously losing [Seabrook] is not ideal, but we kind of had a game last year where we lost [Keith] and the other guys had to step in and play more minutes and bigger roles and do a better job, and I think that's something we have to look at. We don't know what's going to happen. But we'll see and we'll adjust."