He usually just goes about his business in a quiet workman-like way.
But that doesn't mean when it comes to goals, Timmons hasn't set some lofty ones for himself.
Heading into his fourth NFL season and second as a starter, the 24-year-old Timmons has sacks on his mind. And lots of them.
"Sacks, that's definitely where the money is. I always love the sacks," Timmons said at the Steelers' training camp at Saint Vincent College.
"I had seven last year, and I feel like I could have had way more. I'm definitely going to be in double digits this year."
For a player not given to bravado, it's a bold guarantee.
The 2007 first-round draft pick feels that in Pittsburgh's attacking 3-4 defense, there will be plenty of sacks to go around. Though he also expects outside linebackers James Harrison and LaMarr Woodley to be in double digits in sacks again, Timmons feels there will still be plenty of opportunities for him working from an inside linebacker spot.
"I'm in the nickel package and we blitz a lot on third down," Timmons said. "And in base, we blitz too. I can see myself getting some blitzes there and capitalizing on getting a lot of sacks."
Timmons recorded his seven sacks in only 14 games last year. He missed two games with a hamstring injury that nagged him all season. He missed the opener against Tennessee with the injury and also sat out a game at Denver in Week 9.
Though Simmons did not start a game in his first two years, the Steelers felt confident enough in his ability that it granted starter Larry Foote his request to be released following the 2008 season, opening a spot in the lineup for Timmons.
"It was one of those things where I just saw that Lawrence was ready to play," said Foote, who rejoined the Steelers as a free agent this season after one year with Detroit.
Despite the injuries, Timmons didn't disappoint, recording 86 tackles and a pair of forced fumbles to go with his seven sacks.
"I hate the fact that I had those injuries that set me back. But it's football," he said.
Timmons spent the offseason working out, trying to better equip his body for the rigors of an NFL season and to avoid a similar fate as last season. He's put weight, and is up to 244 pounds.
But it is not so much the weight as it's how his body has been reshaped.
"I was training two times a day in the offseason for a period, trying to get lean and running a lot," Timmons said. "I run a lot at my position.
"You're always striving to be better. So, hopefully, I'll have a better year than I had last year."