Mike Wells of ESPN.com provided the update Saturday, but he noted it's possible the organization may still interview another candidate before making a choice. On Sunday morning, NFL.com's Ian Rapoport reported McDaniels is "the clear favorite," and "the belief is he takes" the position.
Indianapolis' front office could face a timing problem.
The team might not have an opportunity to schedule a second meeting with McDaniels until after the AFC Championship Game next weekend now that the Patriots advanced through the divisional round with a victory over the Tennessee Titans on Saturday night, per Wells.
Meanwhile, Vrabel is under consideration for the Detroit Lions' job, making it unclear whether he'd wait for a decision. However, ESPN.com's Adam Schefter reported Sunday morning Patriots defensive coordinator Matt Patricia is likely to be named the Lions' head coach.
Colts general manager Chris Ballard said in early January there was no timetable to make a selection after the team fired Chuck Pagano following a 4-12 campaign.
"Is resume important? Yes," Ballard told reporters. "But I think there's many instances through history that coaches have been hired from places that didn't [succeed]. I know [Steelers coach] Mike Tomlin was 8-8 and Pittsburgh hired him from Minnesota. I think Mike McCarthy was hired and they were 2-14 in San Francisco when Green Bay hired him as head coach."
Potential success in Indianapolis is heavily tied to the health of quarterback Andrew Luck.
He missed the entire 2017 season due to lingering shoulder problems, but team owner Jim Irsay insisted he'll be back on the field.
"He's coming back, he's coming back," he said. "You guys don't know the fire that's burning in Luck's eyes. You guys don't know the type of fever he has for success right now. It's a 107-degree fever towards success right now, the intensity that he has."
The Colts offense dropped from 10th to 31st in yards per game without Luck. His availability is the most important factor in the team's future success regardless of whether McDaniels, Vrabel or a dark-horse candidate is hired as the next head coach.