The Indianapolis Colts were set to officially announce McDaniels as their head coach on Wednesday, before he decided not to accept the job on Tuesday.
Sources within the organization told ESPN that Belichick told McDaniels "I want you to be by my side. I'm going to open my world to you. Show you how I do roster building, how I look at financials and the salary cap."
The report stated that McDaniels viewed the opportunity as "extremely valuable." The Patriots also "sold" McDaniels on the fact that his kids would "have stability" with him staying with the franchise, according to the report.
ESPN also reported that the Patriots were able to make a time-frame commitment with McDaniels. The report stated that McDaniels did not have that information before agreeing to be the coach of the Colts.
McDaniels met with Belichick and owners Robert Kraft and Jonathan Kraft Tuesday at Gillette Stadium. He arrived at the stadium with intentions of cleaning out his office and accepting the Colts job.
The 41-year-old offensive coordinator began his NFL career with the Patriots as a personnel assistant and coaching assistant in 2001. He continued his role as a coaching assistant in 2002 and 2003, before being promoted to quarterbacks coach. He took on the offensive coordinator role in 2006, before being hired as the Denver Broncos' head coach in 2009. McDaniels was fired after Week 13 of the 2010 season and became the offensive coordinator and quarterbacks coach for the St. Louis Rams in 2011. He assumed that role again for the Patriots in 2012.
McDaniels owns an 11-17 record as an NFL head coach.
After news broke of his decision, former Colts coach Tony Dungy had some strong words for McDaniels.
"Haven't read the article but I can tell you there is NO excuse big enough to justify this," Dungy said in a response to a tweet from the MMQB. "It's one thing to go back on your word to an organization. But having assistant coaches leave jobs to go with you then leave them out to dry is indefensible. For COMFORT??"
The Colts released a statement after McDaniels' decision, cancelling its scheduled press conference with the would-be coach.
"After agreeing to contract terms to become the Indianapolis Colts' new head coach, New England Patriots assistant coach Josh McDaniels this evening informed us that he would not be joining our team. Although we are surprised and disappointed, we will resume our head coaching search immediately and find the right fit to lead our team and organization on and off the field," the statement said.
"The scheduled press conference at Lucas Oil Stadium will not take place tomorrow. More information will be forthcoming."
Colts general manager Chris Ballard held a press conference on Wednesday to talk about the latest sequence of events.
"I want someone who is 100 percent committed," he told reporters.
"I didn't want the explanation. You're either in or out. Josh McDaniels is a good football coach and I wish him the best moving forward."
The Colts will continue to honor the contracts of the assistant coaches hired to serve on McDaniels' new staff.
McDaniels' agent Bob LaMonte has terminated his contract with the Patriots assistant after learning of his decision not to take the Colts job, according to multiple reports.
"My word is my bond. Once you break that, there's nothing left," LaMonte told NFL.com.