After John retired, the family settled in Michigan and Jonathan developed his game with the Little Caesars and Honeybaked hockey programs.
John was also developing as a coach and was hired as an assistant with the NTDP in 2011. John helped with Jonathan's teams, but did his best to be a parent rather than a coach from the stands.
"I supported him and always told him be a good teammate and make people better and listen to your coach," John said. "The only thing I can do as a parent is screw it up. I sit back."
Jonathan appreciates the input he's received from his father while also being able to grow on his own.
That includes watching how his father handled an odd situation with Flint of the Ontario Hockey League in 2015-16. John was fired as coach 17 games into his first season, reportedly because the team owner wasn't happy with his son's ice time. A player boycott led to Gruden being re-hired a day later. He eventually was promoted to general manager but was fired again with 15 games remaining in the season.
"He handled it with such class," Jonathan said. "Was a tough situation there. He did everything he could to be with [his players]. That was the No. 1 priority, the team. Luckily, they protested for him like that. It was a huge testament to what kind of coach he is."
Jonathan said his big takeaway was, "Success isn't going to be a straight line. There's going to be bumps along the way. With that, be a great player and a great teammate and great things will happen."
Some pretty good things have happened for Jonathan this season. He's sixth on the NTDP with 49 points (24 goals, 25 assists) in 52 games and tied for second with a plus-30 rating. He started at center but a move to left wing on the top line with fellow 2018 draft prospect right wing Oliver Wahlstrom and center Jack Hughes, a top prospect for the 2019 NHL Draft, has helped unlock his full skill set.
"Long-term he'll be a center, but physically it's hard to him to play a top two-line center role with those defensive responsibilities and produce a lot of offense," NTDP coach Seth Appert said. "When we switched him to the wing his offense came out."