It's fair to assume that Chuck Pagano's days as the Colts coach are numbered. And even though owner Jim Irsay says no determination has been made either way, the signs have been there for months.

CBS Sports NFL Insider Jason La Canfora wrote in September, before the Colts even played a game, that there was growing friction between Pagano and general manager Ryan Grigson. Apparently, a tumultuous season has only exacerbated the relationship. In fact, according to WTHR.com's Bob Kravitz, Grigson's pattern of "meddling" during his four years in Indy helped undermine Pagano.

Kravitz cites several occasions during Grigson's tenure where he and Pagano were at odds, and usually to the detriment of the organization:

1. Grigson reportedly insisted that Pagano play -- and even start -- running back Trent Richardson. The very same Trent Richardson who Grigson gave up a first-round pick to acquire from Cleveland. Also the very same Trent Richardson who averaged 2.9 yards per carry in his first season in Indy, and 3.3 the next, before the team mercifully let him go.

"According to sources, Grigson was concerned with creating the narrative that it was a good trade, something it clearly was not," Kravitz wrote.

That's a hell of a narrative.

2. Grigson reportedly insisted that Pagano use 31-year-old Josh Cribbs at returner last season, even though Pagano was against it. Cribbs fumbled in the AFC Championship Game blowout loss to the Patriots, which is now mostly remembered for Deflategate. Worth mentioning: It was who Grigson informed the league that he had concerns the Pats were up to no good.

3. Grigson reportedly overruled Pagano on at least one occasion when the coach wanted to punish a player. "The culture here now is the worst I've ever seen it," a source told Kravitz, alluding to the frequency with which Colts players have been arrested in recent years.

4. As La Canfora reported in September, offensive coordinator Pep Hamilton was forced on Pagano. Hamilton was fired midseason and replaced by Rob Chudzinski. "Pep was never answerable to Chuck," a source told Kravitz. "Pep answered to Ryan, and everybody in the building knew it."

Kravitz adds, "According to sources, Grigson was overly involved in the coaching side of things since the day both he and Pagano arrived in Indianapolis in 2012, and that nothing has changed."

Grigson's future in Indianapolis remains murky, even if the picture being painted pegs him as mostly responsible for the Colts' current predicament. Either way, La Canfora reports that "Grigson's fate will be determined by owner Jim Irsay's ability to get an A-list coach," though we can't imagine an A-list coach wanting to work with Grigson.

Ryan Grigson and Chuck Pagano have apparently been at odds for some time. (USATSI)
Ryan Grigson (pictured) and Chuck Pagano have apparently been at odds for some time. (USATSI)