Mantha, 22, suffered a setback right when he was turning professional, breaking his right leg during the third game of the 2014 prospects tournament.
Last season, Mantha got 10 games with the Wings, scoring two goals and an assist.
Over the summer, Mantha went to work, putting on eight-plus pounds of muscle by eating seven or eight times a day and spending hours in the gym.
But because he was still exempt from waivers, Mantha was sent down after a strong training camp and preseason.
When his good friend Andreas Athanasiou went down with a knee injury, Mantha got the call, making his season debut Nov. 12 against his hometown Montreal Canadiens.
In his first 16 games this season, Mantha had four goals and three assists.
In his last eight, Mantha has six goals and five assists, including a goal and an assist in the 4-0 win in Los Angeles.
"I didn't think he was quite as good (Wednesday night) but I thought he was really good (Thursday night) so now that's three out of four games where I thought he's been really, really good," Wings coach Jeff Blashill said. "I thought his net presence was great, I thought he moved his feet great. It was a big fourth goal there. But I just thought his approach was really good so three out of four games, he did a real good job,. It's that kind of consistency, it's hard to be a go-to player every night in this league, extraordinarily hard. But you look at his numbers right now, that was his 10th goal in 24 games or something like that. That's a heck of a pace."
Thomas Vanek, one of the Wings' most gifted offensive players, appreciates the growth that Mantha has displayed.
"It's a game of confidence," Vanek said. "He's a big body, he skates. Early on when he came here he was a little tentative, he didn't want to make mistakes. All of a sudden a few goals go in and he's holding the puck more now, looking for plays. It's a different player. Again, confidence does miracles and he's got a lot of it now."
ATHANASIOU LEARNING: Everyone knows that Athanasiou is one of the fastest players on the team.
He also has a lot of skill to go with that.
Yet Blashill chose to sit Athanasiou Wednesday night in Anaheim.
Blashill didn't go into detail about what he said to Athanasiou, but said, "I expect our guys to come and work and compete every day, in games and practices. Every. Single. Day. That's all I'm going to say about it."
Athanasiou got back in the lineup against the Kings and had his first career three-point game, assisting on both of Vanek's goals and scoring on a breakaway.
"He was excellent, excellent in the first, excellent in the third, I thought in the second maybe didn't skate quite as well but he was excellent in the first, excellent in the third," Blashill said. "When he's that determined, he's got big-time talent. You guys know it, I know it. As I said to him today, ultimately we're a better team when Double-A's going at a high level and he was going at a high level tonight. So now the challenge for every player is to follow that up again Saturday against San Jose."
Goaltender Jared Coreau knows Athanasiou well from their time together with the AHL's Grand Rapids Griffins.
"He's got world-class speed," Coreau said. "I don't know if there's anyone faster. When he gets a breakaway, there's no one really that can catch him that I've seen anyways. Like in Grand Rapids he can do the same thing, maybe even faster. When he gets going, he's a good player."
Blashill put Athanasiou on a line with Vanek and Frans Nielsen, two established veterans.
"Those are two unbelievable players, so, obviously, my speed can complement their game and open up ice for them," Athanasiou said. "I think right off the bat we had offensive zone going, the puck moving well and found the back of the net the first shift, which is always nice and kind of build off that the rest of the game."
Vanek said with Athanasiou, it's similar to Mantha with his confidence growing.
"When he feels good about his game, you see a player like this (Thursday night)," Vanek said. "It's Fransy and my job to keep him honest, keep making sure he does his things. Like I said, he's a special player. We've got to make sure he feels good about his game because then he can make a difference."
DEFENSE CHANGES: With the lower-body injuries to defensemen Brendan Smith and Niklas Kronwall, the Wings put Alexey Marchenko and Ryan Sproul in the lineup against the Kings.
Marchenko was returning from missing the last eight games with a shoulder injury.
"I thought our D corps was excellent (Thursday), to be honest with you," Blashill said. "I thought Marchenko came in, did a real good job for being out, I don't know, I think it was four weeks. I thought (Nick) Jensen was excellent, I thought (Xavier) Ouellet was great, I thought (Jonathan) Ericsson was great, I thought DK (Danny DeKeyser), really, you go down the line, I thought they were all really, really good. I thought they moved the puck better, I thought they skated better than they did (Wednesday) night, and they had to defend against a group that I think is extremely hard to defend against. I was really happy with our D corps."
Ericsson assisted on Vanek's second goal, played a team-high 23:13 and finished the night a team-best plus-4.
Jensen assisted on Mantha's goal, had two shots, one hit and three blocked shots.
DeKeyser had a team-high four blocked shots.
NATIONAL PRIDE: Blashill was focused on his own team but that doesn't mean he didn't take a quick look at the world juniors championship game between Team USA and Team Canada, won by Team USA in a shootout.
"I just want to make sure I congratulate (Team USA general manager) Jim Johannson, (Team USA head coach) Bob Motzko and the whole USA staff on a big-time win at the world junior championship," Blashill said after Thursday night's shutout victory. "It's outstanding for them." Blashill said they watched a little during the first intermission. "We were watching clips of our game and we were watching the shootout at the same time," Blashill said. "I was mega pumped up. Bob Motzko did a great job and great job to the US staff. I think it's awesome."