MINNEAPOLIS -- When the Minnesota Vikings and New York Giants take the field in front of a national TV audience Sunday night, there will be one particularly interested viewer in Florida, his mind invested and his heart divided.

To many, Bill Parcells is synonymous with the Giants, having led them to their first two Super Bowl titles in his 10 seasons as head coach. Parcells hired Giants head coach Tom Coughlin to be his receivers coach in New York; he grew up following Frank Gifford and Sam Huff as a child in Engelwood, New Jersey.

Mike Zimmer will surely be receiving a congratulatory message from Bill Parcells, his former boss in Dallas, should the Vikings clinch a playoff berth this Sunday. Brad Rempel/USA TODAY Sports

But to Vikings coach Mike Zimmer, Parcells is a mentor and confidant, who kept Zimmer as his defensive coordinator when he became the Dallas Cowboys' head coach in 2003, and often told Zimmer, "Mike, write this down for when you're a head coach." Parcells' sayings reverberate through the Vikings' locker room in Zimmer's voice. When the coach gave every player a game ball after Sunday's win over the Chicago Bears that got them to 9-5, and told them, "They can't ever call you a loser again, because we're winners from now on," Parcells said the same thing when the Cowboys won their eighth game in 2003.

Parcells, now 74, is five years removed from running the Miami Dolphins, and his only official connection to the NFL is as a courtesy consultant for the Cleveland Browns. He spends his summers in Saratoga, New York, and his winters in Jupiter, Florida, "racing horses and playing golf."

He also watches every Vikings game, recording the ones he doesn't see live. He texts Zimmer a comment -- a word of congratulations, an observation or a question -- after every game, and though Parcells downplayed the content of his advice ("Usually, that would be two incomplete sentences -- that's it," he said), it's clear Zimmer regards the texts as treasured gold.

The Vikings-Giants matchup, then, involves two of Parcells' colleagues, a decorated member of his fabled coaching tree and a newer one for whom Parcells vouched a year ago. Suffice it to say no sides will be taken by the Hall of Famer.

"I’m just looking," he said last Friday. "I’m a Giant at heart -- that’s my team, that’s what I grew up watching. I'm always interested in the Giants, and have a high regard for Tom Coughlin. But to be honest with you, I'm going to try to find out what the heck’s going on here. It's just, 'Let’s see.' I'm not rooting for or against anybody. I have a vested interest in both of those people."

When the Cowboys hired Parcells, Zimmer had already been in Dallas for nine seasons, working as the Cowboys' defensive coordinator for the previous three. Dallas was running a 4-3 defense, and Parcells eventually wanted to switch to his familiar 3-4 scheme. But in Zimmer, he saw a devoted teacher who could run either system, and a kindred spirit whose approach carried a familiar candor and drive.

"I tried to take him aside from time to time and talk to him about some situational things, things that were going on with the team -- 'When you’re a head coach, I just want to explain to you why I’m doing what I’m doing,'" Parcells said. "I thought he had potential, but you’re never sure, because you can’t explain what being a head coach is like and how it’s different than being an assistant. People have to go through it, and never know how it’s going to happen. But I’m very happy that he’s got the chance. I think football needs guys like him.

I think he stands for the right things in terms of coaching, evaluation of players, makeup of players. I think he’s honest, tough and he’s not afraid of confrontation. I think those things are all good."

Bill Parcells said he saw Mike Zimmer as a potential NFL head coach over 10 years ago when they worked together in Dallas. "I think football needs guys like him," Parcells said. AP Photo

Zimmer had been turned down multiple times for head coaching jobs before his name surged to the top of the Vikings' list of candidates to replace Leslie Frazier after the 2013 season. The Vikings' owners, Zygi and Mark Wilf, had been devoted New York Giants fans growing up in New Jersey, but Parcells said his contact was more with Vikings GM Rick Spielman when the team was interviewing Zimmer.

"Rick called me and asked me about Mike," Parcells said. "I said, 'I think you would like him. I think you would have a lot in common.' I think it’s worked well so far."

The partnership has worked well enough to take the Vikings from 5-10-1 in 2013 to 7-9 in 2014, and back to playoff contention in 2015. There's no big secret that Parcells has for Zimmer when the Vikings eventually get to the playoffs, other than the importance of time management as he prepares for multiple opponents.

Even with the Vikings on the doorstep of a postseason berth, Parcells assumes nothing, and risks jinxing nothing. "Whoa!" he yells at a reporter who begins a question with a playoff spot as a presupposition. "We've got three more games left!"

His words of congratulations will flash across the screen of Zimmer's phone if the Vikings clinch a spot this Sunday, but from what Zimmer has learned from Parcells, he's not going to be satisfied with that milestone. And with how devoted Parcells is to the goodwill of his former coaching pupils, a Vikings playoff game won't be light viewing.

"I've gotta tell you," he said, "I can’t get the opposing quarterback down sitting on my couch. I'm twisting and turning and trying to get him down, but can’t get him down from my couch. When you’re watching people you care about coaching the game, and you have a trained eye, that's not the easiest thing to undergo. [The teams] do some things you like. They do some things that get you pissed off, but that’s OK."