TAMPA, Fla. -- Tampa Bay Buccaneers rookie running back Jeremy McNichols had one way to describe his NFL experience after his final preseason game Thursday night: humbling.

The fifth-round draft pick out of Boise State nicknamed "McWeapon" came in with all sorts of expectations, with some even suggesting it was a sign of things to come for Doug Martin or possibly Charles Sims. His college production in three years had eclipsed what Martin managed to do in four, and the front office was raving about his hands.

Instead, McNichols may not even end up on the 53-man roster.

"This was a really humbling experience coming in, to be honest," McNichols told ESPN. "I really had to dig deep to find who I really am and who I really want to be as a football player."

And who is that he wants to be?

"I want to be the best I can. I want to continue to progress as much as I can," McNichols said before a lengthy pause.

"It's never going to be enough."

By the looks of things, his performance this preseason won't be enough to make the Bucs' 53-man roster, which is bad considering that 33 of the 36 players drafted in fifth round of the 2016 NFL draft played in at least one regular season game, according to ESPN Stats & Info. In 2015, 32 out of 40 players drafted in the fifth round played in at least one regular season game that year.

McNichols' struggles have played out across multiple episodes of HBO's "Hard Knocks." Both head coach Dirk Koetter and running backs coach Tim Spencer said he "needed to get in his playbook more."

McNichols said he tried to "block out the noise" as much as he could and focus on the things he could control, like spending more time in the film room and studying with teammates.

But he still has been behind grasping the offense and has been struggling with protections. He gave up a sack in the third preseason game and was yanked after just two snaps because Koetter said he was "making too many mistakes." Koetter also said he was going to get "one final shot" to prove himself this week.

That "final shot" came against the Washington Redskins, where he rushed for 36 yards on 10 carries.

What did Koetter think of that? By the sound of it, not much.

"Yeah. I don't know," Koetter said. "I probably better take a look at the tape."

Koetter sounded a bit more optimistic on Friday.

"It was great for him to get 10 carries. We were carrying seven halfbacks for most of camp, so to get 10 in a game [is helpful]," Koetter said. "I thought Peyton started out strong, and it was good to see Jeremy get his 10 and he also got some time on special teams. We got to see him more in protection. I feel like last night was a great opportunity to get a true evaluation of where Jeremy is right now."

Those within the organization are still trying to figure out why McNichols has struggled. He's a player who general manager Jason Licht said had "rare hands" and was "one of the best pass-protectors in the draft [at] that position." McNichols also said when he was first drafted that he felt like pass protection was a strength of his.

Was Koetter's playbook too difficult to grasp? Did he miss out on valuable coaching while he was recovering from a shoulder injury? Was this more than he bargained for?

“No, because even in college it didn’t come easy," McNichols said. "I made mistakes in college as well early on, even throughout my sophomore and junior year – not as many of course, but you just have to trust the process. It’s all part of the process."

“I expected that, McNichols said. "You’re going to mistakes. You’re learning a new system, a new playbook, a new environment – everything is new – so you’re going to make mistakes, but you’ve just got to continue to learn quick. It’s the NFL, so you’ve got to learn quick. You don’t really have a lot of time.”

His time may very well have run out. The Bucs already have Martin, Sims and Jacquizz Rodgers, and Peyton Barber has progressed nicely in his second year in Koetter's system. Though their numbers were similar Thursday night, Barber looked far more explosive, especially in short yardage. Even with Martin serving a three-game suspension to start the season, there would be no need to carry five running backs.

Unless the Bucs want to give him more time to learn their system and feel he's in danger of being scooped up by another team, the best-case scenario for him, at this point, would be the practice squad. After cuts are due at 4 p.m. Saturday, teams will begin assembling their 10-member practice squads Sunday.

"I've still got a lot to work on," McNichols said. "I had to really go back and check myself and it did make me have a bigger chip on my shoulder moving forward. But it's still not good enough."