When he felt his knee go he lunged forward for the goal line. Grossman didn't find out he scored a touchdown until after the game, but it didn't take him long to realize the severity of the injury.
"I knew instantly because it felt really bad and I've never really been injured," Grossman said. "Soon as I planted, I knew I was done. It's a terrible feeling."
Grossman is scheduled to have surgery in two weeks and tried to keep a sense of humor about the situation and seven to ten months of rehab.
"If you're going to go out, you might as well go out scoring a touchdown I guess," Grossman said.
The harsh reality for the Bears is that Grossman was taking huge steps toward becoming the leader of the offense since throwing an interception in the end zone in the season opener against Detroit.
Offensive coordinator Terry Shea spent tireless hours working with Grossman in preparation for the season and saw the hard work paying off.
After throwing two interceptions and no touchdowns against the Lions, while completing just 16 of 35 passes, Grossman got off to a shaky start vs. the Packers. On his first four dropbacks, he had two incompletions and was sacked. A few plays later he was picked off four yards from the Packers' end zone on an awful throw.
"He came off the field, and he just has that composure that you really, really appreciate in a young quarterback," Shea said.
After the first quarter, Grossman was neither sacked nor intercepted at Green Bay. Against the Vikings he completed 21-of-31 passes for 248 yards and with no interceptions, but fumble the ball inside the red zone trying to stay alive on a play.
Grossman engineered two fourth quarter touchdown drives and if he hadn't gone down would have had a chance to win the game.
"For Rex to have the performance that he had and you could feel it on the sideline that the guy was really magic in a lot of ways," Shea said following the loss to Minnesota. "Consequently you said ‘man the sky is the limit for this quarterback and for this offense,' but it'll have to be put on hold for a while."
Grossman is expected to make a full recovery, but Shea knows first hand that a knee injury to a quarterback can limit off-season work. Trent Green was unable to take a snap with the team until training camp following a serious knee injury the previous season with the Rams.
In the meantime Shea has the responsibility of getting Jonathan Quinn ready to replace Grossman. Quinn threw his first NFL passes since 2001 when he came in after Grossman's knee injury for the Bears' final series and had the chore of trying to drive the team 90 yards 1:36 without a timeout.
"Well, it's my job, it's something that I prepare for," said Quinn, who had three career starts when Grossman went down. "It is a shock at first when you see someone go down and then you have an adrenaline rush. But then again, that's your job and that's what you've got to prepare for."
The seven-year veteran had three career starts coming into the season, but still the Bears voiced confidence in Quinn, who has completed 66-of-125 for 748 yards, but they really have no other choice with Grossman out. The other quarterback is rookie Craig Krenzel.
"I have liked Jonathan Quinn all along," Lovie Smith said. "We brought him here for this occasion. You didn't want it to happen but things like this do happen. I think he played well in the preseason when he got an opportunity to play."
Former Cowboys QB Chad Hutchinson signed with the Bears to add depth at quarterback. Krenzel will move up to second on the depth chart for now, but Hutchinson could eventually become Quinn's backup. The Bears pursued Hutchinson in 2001 when he gave up minor league baseball for a chance to play in the NFL. He was cut by Dallas before the start of the season, but does have nine career starts in his career.