TEMPE, Ariz. -- Like clockwork, Larry Fitzgerald was yet again the most reliable receiver for the Arizona Cardinals in 2019.

Fitzgerald, 36, led the Cardinals with 75 catches for 804 yards, and the future first-ballot Hall of Famer tied for a team high four touchdowns.

Fitzgerald sitting atop the Cardinals' receiving depth chart during his 16th season speaks volumes about his talent, but it also says something about the state of Arizona's wide receiver room, where Fitzgerald was the only player older than 26 when the season ended. And it raises two questions: How much longer can Fitzgerald do this? And how much longer can the Cardinals afford to not have anyone else step up?

A position that was supposed to be a bastion of youth in 2019 ended up being populated by veterans, leaving the Cardinals' future at the position uncertain with three scheduled free agents among eight receivers on the roster.

Evaluating the rookies

Arizona spent prime draft capital on three receivers in 2019, but they hardly contributed.

• Second-round pick Andy Isabella's rookie season was a roller-coaster ride. He played just 38 snaps in the first eight games before finding a small role in the offense. He established himself as a speedster who was tough to defend in one specific route: Fly. He showed off his speed, and how difficult he is to cover when he gets a step on a defensive back, during an 88-yard touchdown catch against the San Francisco 49ers on Halloween. He finished the season with 189 yards on nine catches. But he played just one snap in Week 17.

• Fourth-round pick Hakeem Butler was put on IR before the season.

• Sixth-round pick KeeSean Johnson, who starred in preseason, was inactive for six games, including the final five, after starting four of the 10 he played in. He had 187 yards on 21 catches.

Coach Kliff Kingsbury chalked up his rookie receivers' ineffectiveness to "just young players learning how to be consistent in everything they do."

"What we teach in practice, being able to apply it week-in and week-out on the field because at this level, doing your own thing just doesn't work," Kingsbury said. "No matter how fast you are, how quick you are, how good your hands are, if you don't have a consistent approach and a plan each and every week, I think they found out, it's tough sledding.

"Talent's not an issue, but I think those guys will mature a lot in the offseason and come back a lot better players."

Kingsbury wasn't caught off guard how steep the rookie learning curve was for Isabella and Johnson.

"I'd say they're where we expected [them to be]," Kingsbury said. "As a rookie player coming in, you're going to have your ups and downs. They both had some ups and downs, but they're both guys that we have a lot of confidence in moving forward. Having an entire offseason here I think will be big for both those guys."

And for now, they'll continue to learn under one of the best receivers to ever play the game.

How much more does Fitzgerald have?

Fitzgerald, who was the only active receiver on the NFL's 100th anniversary all-time team, will return to the Cardinals for his 17th season after agreeing to one-year deal with the Cardinals on Jan. 15. When the season ended, Kingsbury said he would pitch Fitzgerald on returning, but noted that he wouldn't dust off his recruiting skills from his days as a college coach.

"He's pretty wise to the game," Kingsbury said. "He's been pitched about everything on this planet, so I think he sees right through any of my BS probably."

Kingsbury's planned for his pitch to be quite simple: "Please come back."

"That's pretty much it," Kingsbury said. "I don't handle the money or any of that stuff, but please come back. I think he's playing as good as anybody, honestly. You watch what he does week-in and week-out, the little things, the blocking and the toughness that he brings to the offensive side of the football.

"He's just still creating separation. He does it all."

Fitzgerald can still be a productive part of the Cardinals' offense in 2020, Kingsbury said.

"Definitely," Kingsbury said. "You see what he's done every week, and that's with a young quarterback and with an offense that's still learning how to play in the system. He's as productive a player as we've had on this offense week-in, week-out, reliability and catching the football. He's still a huge weapon for us, and I don't see that changing."

A reliable No. 2

The Cardinals have a built-in complement for Fitzgerald in Christian Kirk, who finished his second NFL season with 68 catches for 709 yards -- good for second-best on the team -- and he did it in 13 games despite dealing with an ankle injury that lingered through Week 17. It was the second straight season that Kirk battled injuries. A high ankle sprain sidelined him for Weeks 5, 6 and 7, but it never went away and it impacted his day-to-day performance, from cutting to practicing.

Kirk's ankle was constantly on his mind, especially during contact and blocking. It was rolled up on in each of the last three games of the season, making it tougher to get back to 100 percent each week.

"You try not to act like it's there, but pain is pain," he said. "Just glad I made it through and ready to get it back healthy."

But there's more Kirk believes he can show after failing to play a full season in his first two years.

"I mean, it goes hand in hand," Kirk said.

When his ankle felt good this past season, he felt he was able to make better plays after the catch. In Weeks 15 and 16, Kirk didn't feel like he had anything after the catch, but he's optimistic for the offseason.

"That's one of the better parts of my game and to be able to get that back, I think will be better for me," he said.

Draft and free agency

Fitzgerald and Kirk combined for 58.3% of the receiving yards caught by Arizona's receivers. The rest of the receivers filled specific roles.

Damiere Byrd, whose contract expires in March, was utilized for his speed, and it showed with 359 yards on 32 catches. Pharoh Cooper, who's also scheduled to be a free agent, was cut after the preseason and then brought back, only to catch 25 passes for 243 yards. Trent Sherfield didn't live up to his preseason hype, finishing with 80 yards on four catches.

So after drafting three receivers last year, and Kirk in the second round of 2018, Arizona may again find itself taking a receiver in 2020. With the No. 8 overall pick they could be in contention for the No. 1 receiver on the board: Alabama's Jerry Jeudy or Oklahoma's CeeDee Lamb. Depending on how the top picks shake out, Alabama's Henry Ruggs III or Clemson's Tee Higgins could also be options, albeit unlikely ones.

The Cardinals, who are expected to have more than $65 million in cap space when the 2020 NFL calendar flips, could make a splash in free agency at the position. Among the receivers currently scheduled to be free agents in March are A.J. Green, Emmanuel Sanders, Amari Cooper, Randall Cobb and Danny Amendola.

The Cardinals could do both, signing a veteran to quickly bolster their receiver's room and draft the next best receiver.

"I like what our wideouts did," Kingsbury said. "I like what our offense did. I think it's on us as a coaching staff to maximize who we have regardless of what it is. This is a wideout-heavy draft. There's no doubt there're some great players at that position, but we have to take the best player that makes us better immediately and has the biggest impact for the organization."