SANTA CLARA, Calif. -- As the No. 3 overall pick in the 2017 NFL draft, San Francisco 49ers defensive lineman Solomon Thomas entered his rookie season well aware of the expectations that come with such a lofty draft position.

"I mean, you know, definitely at the beginning of the season, of course," Thomas said. "Then I just calmed down, focused on playing football and having fun. It’s just part of the process of being a rookie -- understanding the pressure and the mental game. I’ve grown a lot, and I’m just going to continue to grow going into my second year."

Thomas' rookie season was something of a mixed bag. Based on the numbers alone, it's fair to say he didn't immediately meet those outsized standards.

Thomas played in 14 games with 12 starts, posting 41 tackles, three sacks and a fumble recovery on 655 defensive snaps. For the most part, he was an effective run defender, finishing tied for second on the team in tackles for loss, with 10. But he often struggled as a pass-rusher, moving around the defensive line as the Niners sought the best place for him to have opportunities to get after the quarterback.

Without a strong pass rush for most of the season, Thomas' inability to consistently help in that regard stood out because of the belief that he was supposed to provide immediate help there. Pro Football Focus gave Thomas a grade of 53.2 for the season, which was better than just nine other first-round picks.

Regardless, the 49ers were pleased with Thomas' progress, noting that he got better as the season went along and as he got further removed from a knee injury he suffered in Week 8 against Philadelphia.

“I’m very pleased," 49ers defensive coordinator Robert Saleh said. "I think we all are, really. He’s a very explosive athlete, he plays really good with his hands, he gets knock-back in the run game. There’s the developmental part that we need to get to with regards to consistency in pass rush, which I think he’ll reach. I’m not really concerned about it. But as far as his growth, I’m very pleased with where he’s at.”

Much of the Niners' belief in what Thomas can become stems from what this offseason could bring. Perhaps more than any other player on the roster, this year's offseason program should offer Thomas a chance to take a big step forward.

Because Thomas attended Stanford, which is on a quarters system and doesn't finish classes until mid-June, he got a late start with the Niners due to a rule that doesn't allow rookies to join their NFL teams until their schools have conducted graduation ceremonies. That cost Thomas all of the organized team activities and left him trying to play catch-up after he joined the team at the start of training camp.

Once Thomas did arrive, the Niners found themselves trying to figure out his best position. He started at the "big" end spot, sharing time with Tank Carradine while also kicking inside to be an interior rusher on obvious passing downs. The 49ers also tried him at the "Leo" spot, rushing from the other edge. All the moving around was difficult for Thomas, especially since he didn't have a full offseason to digest any one position.

"Playing different positions, you’ve got to learn a lot of stuff and do different things," 49ers defensive tackle DeForest Buckner said. "And in those different positions, there’s different skill sets you’ve got to use. It’s a lot of work to do, but Solomon is a great player, and he’s a smart guy, and he can handle all that kind of stuff. At the same time, being a rookie, you also have a big part of the game is the mental part, and he’s really had to get past that part. I feel like he has been throughout the season, and I feel like whatever the coaches give him, he’s determined to get it done."

With so many different jobs on his plate, Thomas often found himself having to re-train his brain on his assignments and techniques whenever he would move to a new spot. Now that he has an offseason in which he won't have to worry about training to run the 40-yard dash for most of it and can divvy up his time focusing on the different spots, Thomas believes it will allow him to polish his pass-rushing skills and begin simply reacting rather than thinking so much.

"I definitely have a lot to work on and a lot of things I need to improve on," Thomas said. "It’s a long season, and I’m just trying to go into next year with that feeling of progressing and trying to get ready for next year and be the best player I can for this team."

So, what are some things he wants to work on?

"Definitely just being a better pass-rusher overall," Thomas said. "There’s a lot of things -- work on your bend, violent hands, get off -- so I’m going to focus on all those things this offseason, and they’ll be a big part of what I key in on these next few months."

Heading toward next season, chances are the 49ers will make finding someone capable of being a dynamic rusher from the "Leo" defensive end spot one of their top priorities in the free-agent market, the draft or both. That should allow Thomas to shift to the "big" end spot on a more permanent basis and then kick inside as a pass-rusher on third down.

In fact, Saleh already said putting Thomas next to Buckner on the interior is where the Niners believe Thomas is best suited as a pass-rusher. That puts the onus on the 49ers defense to get opponents into third-and-long situations on a more regular basis to create opportunities for Thomas to rush the passer.

For now, Thomas knows more will be expected of him in Year 2 and after a full offseason to work on his craft and understand the team's defense. But he doesn't plan to let the pressure take precedence over the process.

"I know it’s going to take time," Thomas said. "I know it’s not going to [happen] right away. I know it’s going to be a little bit, but I’m working my butt off and I’m going to become the player I need to be."