John Carlson's retirement leaves Cardinals with two big, inexperienced tight ends

TEMPE, Ariz. -- And then there were two.

The news of John Carlson's unexpected retirement Tuesday left the Arizona Cardinals without much experience on their depth chart at tight end. Troy Niklas, last year's second-round pick, and Darren Fells, a former pro basketball player, remain as the only tight ends on the roster who caught passes in 2014.

But they didn't catch many. They combined for eight receptions and 109 yards during the regular season.

While Carlson's departure leaves Arizona in a bind, having two young yet large-body tight ends may not be the disaster it implies.

The Cardinals are certainly left with a depleted tight end room. Experience is at a minimum. Niklas, who was drafted as the future at the position, is entering his second season but only played in seven games as a rookie because of injuries. And Fells has only 10 career games to his name.

If Niklas can stay healthy in 2015, he'll have to grow up in a hurry. Fells, whose playing time increased toward the end of last season, will have to focus this offseason on advancing his understanding of the offense, specifically how his blocking fits into it.

A significant part of the Cardinals' offense is based on having two large tight ends as the bookends on the offensive line. This time last year, the Cardinals' had enviable depth at tight end: Carlson, Jake Ballard, Rob Housler and Niklas. Since then, Ballard has retired and Housler was left to walk in free agency. And Carlson retired on Tuesday.

Arizona still has the size coach Bruce Arians likes at tight end -- but not the experience. Both Niklas and Fells can fill roles in blocking schemes and catch the occasional pass. But their inexperience will come into play when it's time to make last-second adjustments to help protect quarterback Carson Palmer.

Carlson's departure means Arizona will be in a rush to add experience.

The Cardinals selected Gerald Christian with the last pick in Saturday's NFL draft, but he's more of an H-back. They signed 6-foot-7, 270-pound Gannon Sinclair out of Missouri State as an undrafted free agent this week, and already had Ted Bolser and Ifeanyi Momah on the roster. The next Fells may be among that group, but Arizona needs a veteran presence.

While the Cardinals begin Phase 2 of their offseason workouts without a veteran tight end, Carlson's absence will be felt most in the tight ends' corner of the locker room. He was the mentor Fells and Niklas leaned on last season, and they could've used his mentoring in 2015 since both were primed for larger roles in the offense. Carlson was the type of player coaches and general managers loved to have on their teams. He worked hard, kept his head down and did his job.

Losing Carlson after the draft wasn't ideal. The Cardinals' approach would've been different if they had known they were losing a starting tight end.

But if Carlson decided to retire because of his history of head injuries, he isn't to blame for putting Arizona in a bind. With young children, Carlson needed to look out for himself first -- even if retirement came a year too late. He reportedly flirted with the idea after the 2013 season in Minnesota. But it's tough for professional athletes to hang it up when they know they can still play on Sundays. He gave it a try anyway, as did the Cardinals. Carlson didn't live up to expectations in 2014, as he caught a case of the drops midway through the season.

Those targets will go to Niklas and Fells in 2015.

Beyond them, the Cardinals need to find a way to rebuild their tight end room. And fast.