KANSAS CITY, Mo. — When David Culley first got to know Jeremy Maclin, the young wide receiver was just another rookie fresh out of Missouri trying to learn his way in the pressure-cooker NFL.

When they reunited this past offseason, everything had changed.

For one thing, Culley is the wide receivers coach in Kansas City these days. And Maclin is a veteran who made such a strong impression on Culley and coach Andy Reid during their days in Philadelphia that they snapped him up as a free agent this past offseason.

"When I got him as a rookie, you know how all rookies come in," Culley said. "He was a first-round pick. But I’m going to tell you something — loved the kid. And getting to know him years later, I’ll tell you what: He’s a consummate professional. He knows our offense. He’s been in this thing before, his leadership. He’s grown tremendously since then."

Maclin had the finest season of his six-year career in 2014, catching 85 passes for 1,318 yards in an offense that never really suited him. So when the Chiefs dangled a $55 million, five-year pact in front of him, Maclin saw the potential in the opportunity.

He could slide seamlessly into a familiar offense, one that could utilize his speed and ability to stretch the field. He could be the top target for a stable quarterback in Alex Smith. And he could be the veteran presence in a revamped wide receiver corps.

"He’s just a more mature player," Culley said. "He knows now what the game is about in the NFL. He knows what it’s all about. He’s been a consummate pro, even when he left Philly to come here. Obviously, he has had tremendous years up there, obviously the last year being his best year, which just goes to show the maturity that he’s had since he’s been in the league."

That maturity will certainly come in handy this season.

After the Chiefs failed to get a single touchdown reception out of their wide receivers last season, they decided to turn over virtually their entire corps. Franchise cornerstone Dwayne Bowe was let go in a cost-saving move, and several unproductive players were allowed to walk.

Maclin was signed to anchor the group, and the Chiefs lavished a third-round pick on Chris Conley, a rangy speedster out of Georgia who could become their No. 2 wide receiver.

The rest of the position group is a crapshoot. Albert Wilson is quick but undersized, Jason Avant is 32 and on the downward side of his career, and Da’Rick Rogers, Armon Binns and Kenny Cook are among those fighting for a roster spot who have yet to accomplish much.

All of which means the pressure will be on Maclin to produce.

For that reason, Maclin has been spending extra time with Smith after practice. The pass-catch combination has hooked up hundreds of times, trying to build chemistry.

"What we’re looking forward to doing, I don’t think you can judge it by completed balls," Maclin said. "I think it’s all about getting to know each other and getting our timing down. I think we’ve gotten off to a pretty good start doing that."

Lookin’ good! Flip through our photo album of Chiefs cheerleaders.

As for the rest of the group? It’s the quintessential work in progress.

"It’s tough early with these rooks and they’re kind of spinning around," Smith said. "It’s just a matter of obviously understanding what you’re doing mentally and fine-tuning and really kind of getting into your craft, and becoming the best at what you can be out here."

Conley certainly has the physical tools. So do a few others on the roster. But perhaps the biggest key to whether the group is able to produce is De’Anthony Thomas, who played a little bit of running back last season but has spent his entire offseason with the wide receivers.

Not surprisingly, the diminutive second-year pro has been looking up to Maclin and Avant.

"Just two professionals that have been in the league," Thomas said. "They know everything about being a pro and just how to be successful and just stay healthy."

The regular season is still months away. But as the Chiefs wrap up their final week of optional workouts, Reid seems impressed with the progress of the wide receivers.

"Well, you’ve got two seasoned veterans there with Mac and J, so both of those two work hard, they’re good route runners, they understand how to practice, there is no wasted time, they’re professional, so that’s important," Reid said. "That speaks volumes to your young guys. They’re going to kind of emulate what the good players do."