It started when he tore the anterior cruciate ligament in his right knee during the second Senior Bowl practice in January. It continued after he fell to the fourth round of the NFL draft in May. And it surely didn't help that he spent the first 11 weeks of the NFL season on the sideline, waiting for a chance to get back on the field.
All that bottled-up emotion came out Sunday after he picked up a fumble and raced 41 yards the other way for his first NFL touchdown.
Colvin danced in the end zone, on the sideline and again in the locker room.
The Jaguars (2-10) should be the ones really celebrating. Although it's still early, the former Oklahoma standout looks like a draft-day steal for the rebuilding franchise.
''The touchdown was a great feeling,'' Colvin said. ''Everything paid off. I had a smile on my face the whole day. Everything was surreal.''
Colvin's scoop and score was a huge play in the 25-24 victory over the New York Giants. It put Jacksonville ahead for the first time after trailing 21-0 late in the second quarter. It also gave the Jaguars two defensive scores in the same game for the first time in franchise history.
But it wasn't the rookie's only play that caught coach Gus Bradley's eye.
Bradley said Monday that Colvin covered the slot so well that Giants quarterback Eli Manning had to move to a different read at least four times.
''He's done a nice job,'' Bradley said. ''He had a big impact now. There were multiple times where Eli went back and was going to try and hit the slot. By the way he played it, it took that read away and he went to the other side, so you saw him have an impact in that way. His grade was close to every four plays he had an impact on the game, and that's really difficult to do at the nickel position.
''It's pretty cool to see how he's come along.''
Bradley said Colvin could end up emerging as a starter opposite former seventh-round draft Demetrius McCray. McCray has been impressive since replacing injured veteran Alan Ball and could be a long-term solution in Bradley's aggressive, bump-and-run defensive scheme.
Colvin could be another piece, possibly replacing up-and-down starter Dwayne Gratz.
''As he progresses, that will be something that we look at,'' Bradley said. ''But right now I think the learning curve for him at nickel everything is new to him. He did much better (Sunday), so I would say as he progresses he could be a guy that gets some looks on the outside as well.''
It surely wouldn't surprise Colvin, whose confidence never wavered through the injury.
''Whenever I play, I'm going to make plays there,'' he said.
Since Colvin expected to be a first-round draft pick, he was somewhat disappointed when he was still on draft boards in the fourth round. He even forgot a conversation he had with Bradley at the NFL Combine in February. Colvin was a month removed from knee surgery and in Indianapolis to meet with teams when Bradley pulled him aside and said, ''We still love you. I'm going to come get you. You can bank on that.''
Colvin forgot about the conversation - until the Jaguars called him on draft day.
He spent the next six months getting back to full speed and finally made his NFL debut Nov. 23 at Indianapolis. He finished with one tackle.
His second game was much more memorable.
''It felt great,'' he said. ''It kind of just brought me back a little and opened my eyes that everything paid off. It took me a lot to get here - 11 months of rehab. The first game, there's always going to be growing pains, but I harp on myself to get better and come back the next week and make plays.''
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