The Johnny Manziel experiment in the NFL may not be done just yet. Although Manziel hasn't worn an NFL uniform since 2015 with the Cleveland Browns, the former Texas A&M star and first-round draft pick remains intent on resurrecting his football career.

After seemingly getting his life together off the field following multiple incidents which led to teams in the league having no interest in the former Heisman Trophy winner, Manziel is giving the NFL another shot in hopes of getting that second chance that doesn't come often troubled quarterbacks.

In an effort to show he's still capable of playing at the highest level, Manziel attended San Diego University's pro day and went through a workout with NFL teams in attendance. Manziel had what is being referred to as a “strong day” in front of 12 teams, according to ESPN's Adam Schefter.

At this point, it is more than likely a long shot that Manziel receives a call with an opportunity. Although Manziel was as talented and entertaining as they come at the quarterback position during his time with the Aggies, persistent off-the-field issues aren't something NFL teams deal with at his position. He may have cleaned up his act and it's possible he impressed those in attendance, but a team taking a gamble on the 25-year-old is another story entirely.

In two seasons with the Browns, Manziel played in 15 games with eight of those on-field appearances being as the starter under center for Cleveland. The former first-round draft pick threw for 1,675 yards, seven touchdowns, and seven interceptions with the team winning only two of the eight games in which he was the starting quarterback.

With so many talented quarterbacks in the 2018 draft class and a number of backups around the league already taking up spots on depth charts, it'll be interesting to see if Manziel gets an invite to a training camp in the coming months.