Wide receiver Jeremy Maclin missed his seventh straight practice Wednesday afternoon, just three days after missing his second straight game.

Maclin originally injured his groin during practice on Wednesday, November 2. That Sunday, he started against Jacksonville, but left the game after just two plays.

Since then, second-year player Chris Conley has taken the reps as the Kansas City Chiefs' No. 1 receiver, leading the team in snaps at the position now three weeks running. No skill-position player took more offensive snaps than Conley last week against the Tampa Bay Buccaneers.

"His role has expanded," co-offensive coordinator Brad Childress explained Wednesday afternoon. "As I've always said, Chris has the ability to be a multiple-position guy. He's got the mental aptitude to be able to do that, as well as the physical skills to be able to do that, so he's a valuable guy for us from the standpoint that you can't really overload him and he can plug in at different spots if somebody needs a breath, or a drink of water or tweaks a hamstring or something like that."

To date, Conley has surpassed nearly every statistical category from his rookie year only 10 games into the season. His receptions are up, his yards receiving are up and his targets are up. Not including Maclin, Conley leads all wide receivers in targets from quarterback Alex Smith.

"I think he's made so much progress," Smith said Wednesday. "I think he continues to grow and see things well. He makes plays out there. The guy has had so many strong catches this year, big plays for us. I think he's someone we look to continue to grow with—I know I do."

Smith proved his statement as early as Week 7 on the field against the New Orleans Saints.

Facing third-and-17 and leading by 10 late in the game, Smith snapped the ball in the shotgun formation. Conley ran a perfect corner route just beyond the first-down marker, and Smith hit him just as he was popped and pushed out of bounds by Saints cornerback B.W. Webb.

The play was so close to the naked eye that the Saints challenged, but you could see Conley kept two feet in bounds and secured the ball as he fell to the ground on instant replay.

"It's good for us to be able to work with each other this season," Conley said after that game. "It's been different because we've had a lot more time to work on plays like that. Sometimes when plays break down, or plays where he's got to get the ball out quickly, placement, where he wants me, what I'm most comfortable with and what he is—when you can put those things together, it allows for plays like that."

Asked about the spectacular toe drag that led to the completion, Conley said it's part of the reason he "champions the little things," which include spending extra time in the playbook or something as simple as body management.

"He's an extremely self-motivated guy, whether it's taking care of his body in the cold tub, in the weight room or getting all his faculties back," Childress said. "It's a race to Sunday. Those guys always don't feel great after 50 or 60 plays of getting knocked around—he does all that stuff."

It's one of the reasons why Childress said he sees Conley as a primary receiver in this league and how he has already outperformed most of the first-round receivers in his 2015 draft class despite being a third-round pick.

"It comes down to how you practice during the week," Conley said after last week's game. "Coach [Andy] Reid always harps on practicing like you're the starter.

"Once you get on into the season, that might be the case."