5 things we learned in Packers' preseason win in St. Louis

Rookie running back Eddie Lacy made a strong case for the starting position.

Five things we learned from the Packers' 19-7 preseason win over the St. Louis Rams:

1. Eddie Lacy forces Mike McCarthy to think again about the starting running back

Lacy got to work with Aaron Rodgers and the starting offense and he looked every bit like the dominant runner that he was at Alabama. Running off of starting right tackle Don Barclay (which is an interesting development in itself), Lacy's first two carries alone totaled 22 yards. Later, Lacy had an 11-yard run to the left side and also brought in a pass from Rodgers for an 11-yard gain.

Lacy exited the game early in the second quarter when Rodgers did, but not before he had put together 40 yards rushing on only eight carries (5.0 average).

Earlier this week, coach McCarthy said that he would "classify (DuJuan Harris) as a starter on our football team." That could have changed Saturday night with Lacy's performance. With Harris sidelined as he returns from a knee injury, Lacy -- as McCarthy put it after the game -- "clearly took advantage of his opportunities."

2. Johnny Jolly makes a strong case for a roster spot

What a game for Jolly. Three years removed from football, Jolly showed off the skills that made him Green Bay's best defensive lineman in 2009 before his arrests and subsequent prison sentence.

On the Rams' first drive of the second half, Jolly batted a pass into the air that was then intercepted by Jarrett Bush. Jolly used to have a knack for swatting passes. Two series later, Jolly had an interception of his own when St. Louis quarterback Kellen Clemens was picked off by the massive defensive lineman in the end zone.

It was obvious how excited the Packers were for Jolly, with multiple players running up and down the sideline after his highlight play. Before this game, Jolly was teetering along the edge for one of the final 53-man roster spots. Jolly's impact in this game was so great that it may have been enough to earn him a job.

3. David Bakhtiari shows he still has much to learn

It wasn't going to be all positives all the time for Bakhtiari. Only 21 years old and forced into the starting lineup after Bryan Bulaga's season-ending injury, Bakhtiari was beat badly by Rams defensive lineman Robert Quinn. That led to a sack of Rodgers on third-and-5 in what turned out to be the starting offense's final drive. With Graham Harrell at quarterback, Bakhtiari was called for a false start late in the second quarter.

Bakhtiari wasn't the only Packers player to struggle in St. Louis. James Starks was the third running back off the bench (behind Lacy and Alex Green) and didn't do himself any favors on a crowded depth chart when he fumbled. That was the last carry Starks got in the game, as he was replaced by Green.

Cornerback Brandon Smith also had a really poor performance. The coaching staff knows that Smith is raw. After all, his NFL career began two years ago as a wide receiver. Now 26 years old, the Packers are trying to get him ready to play cornerback. There were very few positives from Smith in this game, though. On special teams, he let a punt bounce off his leg, creating a live ball that was recovered by the Rams. On defense, Smith was beat on a quick double-move late in the fourth quarter that resulted in St. Louis' only touchdown.

4. Mason Crosby takes a step in the right direction in kicking competition

This is the game that Crosby desperately needed. Outkicked by challenger Giorgio Tavecchio throughout training camp, Crosby was the better of the two in this game.

Crosby made field goals from distances of 34 yards, 48 yards and 30 yards. Switching back and forth on field-goal attempts, Tavecchio got his chance on the second one, but he missed wide left from 49 yards out. Tavecchio later connected on a 38-yard field goal.

McCarthy has said that game performance weighs more in the evaluation process than practice performance, so Crosby can fly back to Green Bay with the confidence that he did himself a huge favor with his strong performance against the Rams.

5. Little progress made in the race for the backup quarterback job

In the battle between Graham Harrell and Vince Young for the No. 2 quarterback spot behind Rodgers, the winner was . . . B.J. Coleman?

Harrell played three drives and completed 5 of 10 passes for 44 yard with a passer rating of 62.1. Unlike the first preseason game, when Harrell didn't put any points on the board in six series, he did take advantage of a short field and get the Packers a field goal after his first two drives ended in Tim Masthay punts.

Young was also in for three series, completing 5 of 9 passes for 26 yards and a passer rating of 60.9. Young did run for 7 yards and a first down, as well. Like Harrell, Young's time on the field resulted in one field goal and two punts.

Coleman played the entire fourth quarter and led the Packers to their only touchdown so far in the preseason. Coleman was 8 of 13 passing for 86 yards and the one touchdown and a 106.6 passer rating.

McCarthy is waiting for either Harrell or Young to step up and claim the job, but with neither of them doing particularly well in this game, Coleman might have reentered the conversation.

Follow Paul Imig on Twitter