INDIANAPOLIS -- The rocky relationship between the Indianapolis Colts and running back Trent Richardson built up over time during the 2014 season because of weight issues, accessibility and an absence, multiple sources told ESPN.com.

Richardson, whom the Colts acquired from Cleveland in September 2013, had weight issues during the season, was difficult to get in touch with and didn't tell the team he wouldn't be at the walk-through the day before the AFC Championship Game, a source said. He was suspended two games by the team for missing the walk-through.

He served the first game of the suspension during the AFC Championship Game against New England. His second game will be served next season -- if he's still with the Colts.

Trent Richardson has averaged 3.1 yards per carry during his two seasons with the Colts. Brian Spurlock/USA TODAY Sports

Because of default language in his contract, the Colts could exercise an option to void $3.1 million in guaranteed money owed to Richardson next season. The NFL Players Association would likely challenge that ruling if it occurs.

Things started to change for Richardson against Cincinnati on Oct. 19, when he suffered a hamstring injury and had to sit out the fourth quarter after rushing for 77 yards through the first three.

That's when Richardson's weight issue started to take off. He began the season at 225 pounds, but his weight had ballooned up to around 240 pounds later in the season, according to a source.

Richardson said after practice one day during the middle of the season that he was running extra sprints to work on his conditioning. He denied to the media late in the season that he had a weight issue.

He had shared carries with Ahmad Bradshaw during the first 10 games of the season, but Bradshaw suffered a fractured fibula -- ending his season -- against New England on Nov. 16.

The Colts, according to a source, became frustrated with Richardson because they couldn't get in touch with him and didn't have any communication with him until around 1 p.m. the day after the Patriots game.

Daniel "Boom" Herron outplayed Richardson after Bradshaw's injury and eventually became the full-time starter in Week 16 at Dallas.

Where Richardson stood with the Colts became even more evident when he was listed as the third running back behind Herron and Zurlon Tipton for the wild-card playoff game against Cincinnati and then was inactive against Denver in the divisional round.

"That situation will never happen to me again," Richardson told reporters Jan. 15. "Anybody can quote me, today, because it's never going to happen again."

Richardson then was suspended for the AFC Championship Game because he didn't alert the team he would not be at the walk-through due to a family emergency. He told the team, according to a source, that he didn't call or text because he had phone problems.

Richardson told ESPN.com on the day of the AFC Championship Game that he was "dealing with a very serious family emergency. ... I wouldn't purposely just miss walk-through."

General manager Ryan Grigson declined comment, instead referring to what he said during his season-ending news conference Jan. 23.

"Every situation is different," Grigson said at the time. "Every player and how we deal with them is going to be different. He'll be lumped into that conversation with guys this offseason. Where does he fit? Where is he going? Is his arrow up, down, sideways, 45-degree angle?"

Richardson, the No. 3 overall pick in the 2012 draft, has rushed for 977 yards (3.1 yards a carry) and six touchdowns on 316 carries in his two seasons with the Colts, who acquired him from Cleveland in exchange for a first-round draft pick.

The Colts paid Richardson $1.1 million in 2013 and $2.2 million last season.