THOUSAND OAKS, Calif. -- A January snowstorm on the East Coast might have altered the course of NFL history, especially for two teams on the other side of the country.

Last Jan. 7, a Saturday, the Los Angeles Rams' traveling contingent -- a group composed of chief operating officer Kevin Demoff, general manager Les Snead and senior assistant Tony Pastoors -- was grounded in Boston, unable to depart until far later than expected.

Kyle Shanahan, the Falcons' offensive coordinator who had been heavily linked to the Rams' head-coaching vacancy, was waiting. But he was also very busy. He had already interviewed with the Jaguars, Broncos and 49ers that Friday and Saturday, during the off days of the Falcons' bye week. The Rams wanted to reschedule their sit-down for Sunday, but Shanahan had to go right back to game-planning. They decided to check in the following weekend.

"They told me if I didn’t sit down, they might end up having to move on," Shanahan said, "and I was definitely OK with that. I think it worked out for both parties."

Sean McVay interviewed with the Rams' front-office members the Thursday before they flew east. He impressed them so much that they basically decided they couldn't let him slip away. McVay interviewed with them again the Wednesday after they returned. He was formally hired that Thursday and introduced on Friday, the day before Shanahan's Falcons hosted the Seahawks in their first playoff game.

Nearly four weeks later -- on the Thursday following a Super Bowl collapse -- Shanahan was introduced as the 49ers' new head coach.

Sean McVay (left) was an offensive assistant under offensive coordinator Kyle Shanahan (right) with the Redskins. McVay and Shanahan will meet as the first time as head coaches on Thursday. John McDonnell/The Washington Post via Getty Images

Shanahan recalled that time earlier this week, days before his 49ers host McVay's Rams on Thursday night, and he didn't express regret about how it all went down.

"To tell you the truth, I was so focused on the playoffs at that time," Shanahan said. "I enjoyed my other three interviews, and when it just kept getting pushed back, I kind of had moved on. If they would have waited and something would have happened, I'm sure I would have sat down with them and we would have been able to talk. But I definitely didn't have any regret about the situation."

Shanahan and McVay's relationship goes back to their Redskins days from 2010 to 2013. Shanahan was the offensive coordinator then, working under his father, Mike Shanahan, and looking for a new quality control coach. In walked McVay, 24 and fresh off a stint coaching tight ends in the United Football League.

"I remember it very well," McVay said of his interview. "It was a comfortable rapport that we had right away because you're talking about football and there were some similarities in terms of our background, both having worked with Jon Gruden as a quality-control coach. We were able to speak the same verbiage right away."

Shanahan, now 37, had never met McVay until that day. When he got him in the room, Shanahan said he "could tell within about five minutes that he was going to be a very good coach."

He reminded him of himself.

"We had four good years together," Shanahan said. "I consider him a good friend."

The current incarnation of 49ers-Rams is loaded with familiarity. The Redskins' 2013 staff had nine coaches who will take part in this game, including three from the Rams (McVay, Matt LaFleur and Aubrey Pleasant) and six from the 49ers (Shanahan, Mike McDaniel, Robert Turner, Bobby Slowik, Richard Hightower and Ray Wright). Five coaches were on the same Falcons staff that suffered a heartbreaking loss to the Patriots in Super Bowl LI, including Matt LaFleur, now McVay's offensive coordinator with the Rams, and his brother Mike LaFleur, Shanahan's wide receivers coach and passing-game specialist with the 49ers.

Matt LaFleur spent a lot of time working under Shanahan as his quarterbacks coach and now works very closely with McVay. He said they're "a little bit different personality-wise," but they're both "extremely detailed and two of the most knowledgeable football minds that I've been around."

Shanahan sees a lot of similarities in McVay's offense with the Rams.

"He might have a little bit more Gruden in him, and I might have a little bit more older Denver Broncos and things in me when it comes to the run game and everything," Shanahan said. "But when you turn on the tape, it’s very similar."

McVay calls Shanahan "one of my closest friends." He raved about the way Shanahan sees the game from a 22-man perspective and how his offense can manipulate so many different coverages. He said Shanahan has had "a huge influence on some of the things that we believe in here."

Shanahan initially saw McVay as someone who works really hard, loves dissecting film and takes it personally when he makes a mistake. Shanahan promoted him from quality control coach to assistant tight ends coach to tight ends coach before leaving to become the Browns' offensive coordinator in 2014. McVay replaced Shanahan as offensive coordinator in Washington.

Three years later, McVay got the job Shanahan never had a chance to interview for. Shanahan "wasn't surprised at all."

"Sean's doing a good job," Shanahan said, "and I knew he would."