San Diego Chargers rookie Melvin Ingram throws his weight around

Quentin Jammer is a 10-year NFL veteran, and the San Diego Chargers’ most experienced former first-round pick, but he found himself transformed into nothing more than a common fan last week.

The target of Jammer’s interest during the team’s exhibition opener against the Green Bay Packers was the Chargers’ newest first-round pick, linebacker Melvin Ingram.

“Did I watch him?” Jammer responded to a question, nearly incredulous. “Everyone on our sideline was watching him.”

Ingram satisfied any doubters right away.

In the first quarter, Ingram swarmed past a Green Bay tackle, pressuring Packers quarterback Aaron Rodgers into a hurried throw that was intercepted by cornerback Antoine Cason. Ingram also had two tackles in the game.

“This was my opportunity to play against higher-caliber guys with more strength and speed,” Ingram said after his debut. “I was happy with how it went, because it didn’t seem too difficult.”

Pressuring Rodgers into such a miscue is rare: The NFL most valuable player last season threw 45 touchdowns and six interceptions. Rodgers’ comments after the game are what the Chargers hope to hear from opposing quarterbacks all season: “We screwed some plays up and turned the ball over.”

Ingram was brought to San Diego to cause such disarray.

“That was just me doing what I can to help,” Ingram said, in a heavy Southern accent. Before the draft last spring some NFL scouts said that Ingram’s short, 301/2 inch arms would be a liability.

“It’s always something they find to nitpick you on, and it’s always ridiculous in a case like this, because if you can play like this guy, who cares about the arms?” Jammer said.

Ingram uses criticism as a form of inspiration. As he grew up in Rockingham, N.C., his parents instilled a strong work ethic in their son.

Last season, Ingram helped lead South Carolina to its first 11-win season and a top-10 finish in the Associated Press poll. The 6-foot-2, 265-pound Ingram contributed 10 sacks, 15 tackles for loss and two interceptions for the Gamecocks, gaining first-team All-American recognition.

Chargers personnel were quietly celebrating in April when Ingram dropped unexpectedly to the team, which selected him 18th overall in the NFL draft. “He’s an exceptional player who can do a lot of things,” Chargers Coach Norv Turner said. “I think he was the most complete linebacker in the draft.”

Last year, San Diego’s defense ranked 16th in the league, giving up first-down conversions on 49% of third-down plays and giving up 23.6 points and 346.6 yards a game.

After missing the playoffs the last two seasons, the Chargers are hopeful Ingram’s pass rushing will substantially bolster a defense that will twice face Denver’s Peyton Manning this season, plus road tests against New Orleans’ Drew Brees and Pittsburgh’s Ben Roethlisberger.

Turner said he projects Ingram as an impact player.

Ingram “is going to be outstanding on third down,” Turner said.

Said Jammer: “In this game, you always need someone to get after the quarterback. I know that’s why we targeted him, but I think he’s been even better than what was expected.

“You should see him at practice. He can straight bull-rush linemen or get around you with a serious spin move. He’ll make a huge contribution. This guy is an absolute monster — big, strong and fast, and he has a motor on him beyond what you’d expect. Most guys who rush don’t have all of those attributes.”

Against the Packers, Ingram also flashed his speed, bursting around a right tackle to force backup quarterback Graham Harrell to throw an incompletion. He also caused Harrell to flinch, leading to a sack by a Chargers linebacker on the opposing side.

To bolster their defense, in the off-season the Chargers signed free-agent linebacker Jarret Johnson, who played nine seasons for the Baltimore Ravens. The Chargers are also crossing their fingers that another linebacker, former first-round pick Larry English, 26, finally blossoms into a key player.

“When this defense has been at its best, we’ve had multiple players playing well at the outside linebacker position,” Turner said. Ingram can be part of “the mix of the guys we have. He can learn from them.”

Said Ingram: “I just know that I need to keep getting better in every aspect of the game. You can never be too good.”

lance.pugmire@latimes.com

twitter.com/latimespugmire