Oh sure, "The Great One" was young once, too. Except when Gretzky was 20, he already had 301 NHL points and had won the Hart Trophy twice and the Art Ross once.
Nevertheless, Gretzky, who now coaches Mueller and Hanzal, can sort of understand the trials and tribulations of promising second-year NHL players. Hey, he's at least witnessed others struggle in their sophomore seasons, right?
"Oh there are ups and downs," said Gretzky, the Phoenix Coyotes coach. "Kids are going to make mistakes. Our young kids are good kids and they want to get better. They take their criticism well. They don't look at it as personal insults."
Mueller, 20, and Hanzal, who is 21, have been taking their fair share of criticism of late because, at least so far, Year Two of their NHL careers hasn't been nearly as successful as Year One.
Mueller had 54 points last season, which was third among rookies. With 5 goals and 10 assists in 27 games, he's barely on pace to match that mark this season, which isn't good enough. Hanzal, who had back surgery in the offseason, had 35 points last season. He's on pace -- 6 goals, 10 assists in 27 games -- to better that this season, but not by much.
While the Coyotes rely heavily on Mueller and Hanzal to produce offensively, neither Gretzky nor Phoenix General Manager Don Maloney seem overly concerned about their lack of consistent production so far this season.
"I think I'm still getting there because I didn't practice all summer, I didn't work out," Hanzal, who had surgery in mid-July and didn't return until the very end of the exhibition game schedule, told NHL.com. "It was very tough on me, but now I'm getting there. This is my second season so there is a little pressure on me. Now is the time."
Gretzky and Maloney believe Hanzal's case is simply about his lack of conditioning entering the season. Hanzal is an all-round threat for the Coyotes, but he couldn’t be that for the better part of a month and a half.
"He was probably four or five weeks behind everyone else," Gretzky said. "He played well the first 10 games, but he has played better since."
Mueller's case is a bit more disheartening, but not enough to cause mounting concerns. He showed so much promise last season with 22 goals and 32 assists in 81 games.
In a recent game against the Philadelphia Flyers, Gretzky cut Mueller's ice time, specifically by pulling him off the power play, where he plays the point.
"Wayne said, 'Listen, it's not good enough,' " Maloney said. "There is a fine line you walk with an offensively gifted player that shows flashes of brilliance -- and we need him to be brilliant -- but is yet having some trouble finding some consistency."
Gretzky, while praising Mueller's hands as the best on the team, said part of Mueller's problems stem from the new challenge he faces on a nightly basis.
"Now he's going up against top defensemen, top checking lines," Gretzky said. "It's different. It's a new challenge for him. He's going to get better. We're relying on him heavily to be a big part of our offense."
According to Phoenix captain Shane Doan, Mueller and Hanzal are just going through the natural progression from rookies to sophomores. The potential someone shows as a rookie turns into expectations when they graduate.
Considering these are two top-six forwards on a team starving for offense, something eventually has to give.
"Marty had 8 goals last year, so you'd expect him to mature to 15 or 16, but when you're sitting there after 16 or 17 games with 1 goal and 3 assists you're like, 'Boy, oh boy,' " Maloney said. "That's part of the problem. We need consistent offense from those players."
And in Hanzal's case, consistently strong defense as well, considering Gretzky uses him to kill penalties and take faceoffs in the defensive zone. Hanzal, who was leading Phoenix in faceoffs taken, is winning close to 50 percent of his draws.
"For a top defensive guy, he has he has to continue to evolve that," Maloney said. "I think if you can get over the 55 percent range on average is good."
Their struggles may be magnified now because the Coyotes are one of the League's lowest-scoring teams, but nobody -- not Maloney, Gretzky or Doan -- seem concerned about the long-term futures of Mueller and Hanzal.
Mueller, Maloney said, should become a prolific 85-90-point guy. Doan stressed that he's a big fan of the Bloomington, Minn., native.
Hanzal, Gretzky believes, "has the ability to become much more offensive-minded than he has been. He does so many things defensively, but I know as he gets more confidence here he's going to produce more offensively."
It is, of course, all about patience now. Maloney and Gretzky have no problem with that. They're building this team knowing if they aren't patient they'll lose their minds, but as the pressure mounts on Mueller and Hanzal does that patience wear thin?
"I feel it a little bit, but this year I have some experience so I have to use it," Hanzal said. "I feel comfortable with that. I don't care if there is pressure on me."
Contact Dan Rosen at email@example.com