Then, during the Broncos' six-game winning streak, he was seen running onto the podium while head coach Josh McDaniels was in the middle of a press conference to give him a hug. Everything seemed to be going well in Bronco-land.
Until the end of the year rolls around and Marshall, along with tight end Tony Scheffler, is ruled inactive in a game that could have had playoff implications.
And now Marshall says that he was in the wrong all season long, saying his actions were "unprofessional," and is willing to do whatever it takes to stay in Denver.
"Last year I handled things totally wrong," Marshall said. "I just looked at the business side of things and took things too personally. This year I'm going to remove myself from the situation and let the Broncos decide the direction we're going to go in as an organization."
It would make sense that Marshall was acting out because he took the lack of a new contract as a slap in the face and was unable to separate business from the football field, as has been the case with many players over the years.
If that is the case, it's certainly something that he could have learned to deal with and may be the best team player in the entire league next season. Really, there's no way for us on the outside to know.
The one person who does know, however, is head coach Josh McDaniels.
Marshall's good-guy act may be just too little, too late. There are no signs that McDaniels wants Marshall back and he could find himself on the way out via trade this offseason.
There are certainly 10-15 teams out there that would do a backflip to get Marshall, so trading him and getting some picks in return may be the course of action for Denver.