"Beyond his physical ability, he's extremely smart, one of the smartest guys on the team," Grossman said. "He knows the offense like the back of his hand, and he's a rookie. … He just has a demeanor about him that reassures everybody, 'Hey, I got this.' "
But the Bears suffered a loss of their own, with starting quarterback Kyle Orton leaving the game before halftime after suffering a right ankle injury. An NFL source called it a high ankle sprain and said Orton will undergo an MRI on Monday. He is expected to be out up to a month, so it's highly unlikely Orton will play against the undefeated Titans at Soldier Field on Sunday.
"We just have to hope he'll be back," Forte said. "We have to look forward and get Rex ready."
Grossman didn't need to be the hero Sunday despite entering the game facing a 23-13 deficit. The Bears led 10-0 after the first quarter thanks to Orton's 5-yard touchdown run—the first of his career—and Robbie Gould's 36-yard field goal. But the Bears' defense continued to show a tendency for lapses, allowing the lowly Lions to score 23 points in the second quarter before shutting them out in the second half.
And in stepped Forte, who rushed for just 25 yards on seven carries in the first half but finished with a season-high 126 on 22 carries. While the Bears were thankful for Forte breaking out while Grossman was filling in, the running back repeatedly thanked his offensive line for his first 100-yard game since the season opener in Indianapolis. He averaged 5.7 yards per carry, a dramatic improvement from the 2.8 he had averaged the previous four games.
Forte's punishing running style, and the use of the no-huddle, finally wore down the Lions, who entered the game with the league's second-worst rushing defense. The Bears threw in a couple of new running plays this week in hopes of keeping the Lions off-balance.
Forte carried the ball three times for 40 yards on what turned out to be the game-winning drive—a seven-play, 54-yard march that ended with Grossman's 1-yard dive. The quarterback emerged from the crowd and emphatically spiked the ball, no doubt relieving some of the frustration from hearing fans boo.
In Forte's eyes, the game plan didn't change when Grossman was inserted despite a couple of offensive hiccups.
"Rex knows the game plan too," Forte said. "They both go over it. That didn't slow us down a bit."
But there was an element that kept the Bears from dominating the winless Lions.
"We were beating ourselves in the first half," Forte said, "so we had to come out in the second half and start eliminating the mistakes."
The Bears contributed to the Lions' second-quarter outburst with Devin Hester fumbling a kickoff, leading to Dan Orlovsky's 17-yard strike to Calvin Johnson on the next play.
Fortunately for the Bears, kicker Jason Hanson had slipped and missed the extra point following Kevin Smith's 1-yard touchdown just 13 seconds earlier. That point was the difference in the Lions having to go for a touchdown instead of a field goal in the last seconds of the game.
And the Bears knocked down Orlovsky's final attempt to find the lanky Johnson in the end zone.
The Bears might have to rely more on Forte in the coming weeks if Grossman has to fill in for an extended period of time. Grossman still appears to be just a little rusty despite a 6-yard touchdown pass to Rashied Davis.
Orton was one of the league's hottest quarterbacks, with the passing game averaging 294.6 yards per game over the last three. Grossman could enjoy the same success once he gets his timing down, but having Forte run like he did in the second half Sunday enhances chances of beating teams such as Tennessee, Green Bay and New Orleans.
"Running the ball is going to be huge, especially when the weather changes," Forte said. "I mean, we won't always have ample opportunity to throw the ball when the weather changes.
"In high school, I played in like a hurricane in [Louisiana]. So, I'm sure I can play in cold weather."