New Orleans Saints wide receiver Michael Thomas (13) makes a reception against Atlanta Falcons cornerback Brian Poole (34) in the second half of an NFL football game in New Orleans, La. Sunday, Dec. 24, 2017.

There were times during his rookie season when Michael Thomas looked like a finished product.

The former Ohio State standout did just about everything asked of him. His routes were polished. His hands were unquestionable. He quickly became one of the more lethal weapons in an offense loaded with firepower.

It was hard to find areas where Thomas could improve. Making any complaints about his game last season would have been considered nitpicking. All that needs to be said is the Saints felt so comfortable with Thomas' ability they sent Brandin Cooks to New England for a draft pick that became an offensive lineman.

But that’s the thing about young players. They’re never finished finding ways to improve — the good ones do, at least. As incredible as he's been this season, rookie cornerback Marshon Lattimore will continue to get better as his knowledge of the system and technique improve, which is what New Orleans is seeing happen with Thomas during his second season.

“There’s not a guy with more thirst for knowledge than Mike Thomas,” quarterback Drew Brees said. “He wants the information. He wants to know exactly where to line up and what’s the depth and what’s the timing, the rhythm and then understanding and repping it. His work ethic is second to none. It starts there.

“Then it’s just experience. As you gain experience, as you encounter these things in practice and then in the game, it becomes more second nature. There’s just this kind of ESP that works then because you’re able to fall back on those things.”

It’s easy to see the growth Thomas has made in his second season. His role and usage have expanded in several key ways as he’s continued to grow in the system. One of the easier ones to see this progress is by looking at where he lines up on the field.

The Saints weren’t shy about putting Thomas, who primarily serves as a boundary receiver, in the slot last season. He moved in there 72 times as a rookie, but only caught eight passes for 94 yards. This year, he’s run 110 routes from the slot and leads all Saints players with 46 targets. His 35 receptions and 402 yards from the position also lead the team, according to Pro Football Focus.

Thomas says he likes moving around and that sometimes he gets more advantageous looks on the inside.

“In the slot, sometimes there’s more room on different routes, and it’s more space sometimes compared to the boundary on the short side of the field, and it’s man and stuff like that,” Thomas said.

Thomas has also been targeted on some different routes this season. Last year the rookie did the bulk of his work on curl, slant and crossing routes, catching 63 passes for 674 yards on those routes. While Thomas is still proficient at doing those things (he has 51 receptions for 526 yards on the same routes this season), he’s also added some other tricks to his arsenal.

The biggest difference is that Thomas has become better — or at least targeted more frequently — on out routes. He was only targeted four times on outs last season, this year he’s been had 15 passes come his way on the same route and has caught 13 passes for 99 yards, according to Sports Info Solutions.

“I feel like I’ve just developed my route tree, I guess I would say it like that,” Thomas said. “I feel like I’ve always been able to run the route tree, but I’m just being put in position to show that on Sundays.”

Having a more extensive route tree makes wide receivers harder to defend since cornerbacks can’t cheat and sit back on a handful of routes. And Thomas has unquestionably been harder for defenses to deal with this season.

He already has more catches (98 vs. 92) than last year and more yards (1,151 vs. 1,137) than last year with a game remaining. The growth in numbers might seem small on the surface but gets larger when looking closer. With Brees throwing fewer passes this season, Thomas has accounted for 28 percent of New Orleans' passing yards this season. He was at 21 percent last year.

The number of opportunities for receivers is even lower when you consider that 160 of Brees’ 506 passes have gone to running backs Mark Ingram and Alvin Kamara. But Payton isn’t about to apologize for the way the offense has operated this season.

“Absolutely not. We’re not in the business of playing fantasy football,” coach Sean Payton said. “We really aren’t. We’re in the business of winning. If that upsets all the people that have a player on our offense or our defense that plays fantasy games in the world, that’s tough.”

It might be, but Thomas is still finding a way to thrive and produce at a higher level in an evolving offense.

Follow Nick Underhill on Twitter, @nick_underhill.​