Then Cholowski was sent to Grand Rapids to work on his defensive play for the remainder of the season.
This year, Cholowski did not play in the tournament.
"It was a little bit weird," Cholowski said after the morning skate at the BELFOR Training Center Monday. "I'd done the prospects tournament two years and that kind of gave us a good warmup for training camp and the preseason. This year, a little more rested, I feel like. I actually kind of think I feel better this year. I feel good and I'm ready to go."
As he did last summer, Cholowski remained in metro Detroit to train with other players and work on the things the coaches had identified for him.
"Just being more assertive and aggressive, especially in the D-zone, and making sure I win my battles, kill plays as fast as I can and make sure my gaps are good and then get the puck north as quick as I can," Cholowski said. "They were preaching that a lot to me this summer and I tried to work on it and I feel like I'm doing a better job at it this year so far."
Although there weren't games to play, Cholowski was able to work on those areas all summer.
"It was just a lot of battling, one-on-one battles in front of the net, boxing guys out, getting in the corner and winning the puck and then just moving it up quick, stuff like that," he said.
Especially for defensemen at the NHL level, experience is often the best teacher, particularly when maintaining good gaps with the best players in the world.
"You have to do it a lot, whether it be in practice and then preseason games is a good time to practice it and make sure your gaps are good and you're staying tight," Cholowski said. "That's really all it is. You just have to play games and if you get time in the practice rink, do it there."
The Wings have also used video to help show Cholowski ways to get better.
"Just kind of be myself as far as the offensive side goes and then just watching myself in the D-zone, seeing what I do and seeing things that might work and what might not work, whether it be going into the corner for a battle, them showing me you have to be harder here," Cholowski said. "It's good for me to see that and continue to work on it."
On Sunday night against the Pittsburgh Penguins, Cholowski had 27 shifts for 21:49, had one shot, one giveaway, one blocked shot and was minus-1.
Wings coach Jeff Blashill believes he's seen a lot of growth in Cholowski's game.
"I think Dennis played very well.," Blashill said Sunday night. "I think Dennis has been sharp moving the puck, I think he's been more physically engaged, I think he's ended cycles better, I think he's gapped good. I think he's had a really good start to his preseason.
"He's spent a couple summers here really working. You want to talk about putting the work in, he's done it. So he's put himself in good position after two games, now you gotta keep going."
Cholowski has worked primarily on the power play but is now also getting work killing penalties this preseason.
"Experience, you have to do it to be able to know what you're doing," Cholowski said. "It's a good time for me to work on it right now and get better at it."
Cholowski does have one advantage when it comes to the power play in that he shoots left-handed.
The other top power-play defensemen, Mike Green and Filip Hronek, are right-handed shots.
Oliwer Kaski, who is aiming to make the Wings after signing as a free agent in May, is also a righty, as is Moritz Seider, the Wings' first-round pick, sixth overall, in this past summer's draft.
"The left shot is important on that power play because everybody else is lefty," Blashill said. "When you walk down the wall, you have a lefty up the top to Cholowski, you have a lefty to (Dylan) Larkin, you have a lefty over to (Anthony) Mantha. So now it makes it harder on the penalty kill for sure. Their top forward can't just overprotect Larkin, he's got to be aware of that shot coming back to Cholowski.
"We would prefer a left, if possible. Last year I thought (Niklas) Kronwall did a great job with it but we'd prefer a lefty."
There is a lot of competition for jobs this year, perhaps even more so than last season.
"You're fighting for jobs; everybody wants to win, wants to play well," Cholowski said. "You can't worry about it too much, just put it out of your head and play my game. I had that mindset last year and I'm coming in with the same thing this year."
Cholowski gets his next opportunity tonight on the road as the Wings travel to face the New York Islanders.
HRONEK CONFIDENT: Last year during the preseason, Hronek admitted to not feeling very confident.
That does not seem to be the case this year.
"I think he's got lots of confidence," Blashill said. "He had a really good second half of last year. I think he had a really good world championship. I think he's got a lot of confidence right now. He's played good so far. We don't need him to play good, we need him to play great.
"Hopefully, he keeps moving his game up to where when we play Nashville Game 1 he's a guy that's a legit top-four defenseman. He's gonna get the opportunity to be a top-four defenseman. We need him to be a legit top-four defenseman."
In 46 games with the Wings last season, Hronek had five goals, 18 assists and was minus-10.
In 31 games with the Griffins, Hronek had seven goals, 17 assists and was even.
Blashill believes that Hronek has another level he can reach with his abilities.
"I think consistency," Blashill said. "He's a solid penalty killer right now. I'd like to see him become a great penalty killer. He's a solid PP guy. I'd like to see him become a great PP guy. I think he's a good to real good player on most nights that's becom(ing) a great player. So it's just that consistency of making way more good plays than bad."
GOALIES GOING WELL: They have not been discussed much at all and that means things are going well for Detroit's goaltenders thus far.
"I thought Bernie was really sharp," Blashill said of Jonathan Bernier Sunday. "Bernie's been really sharp since day one, super sharp from day one, to be honest with you. I thought (Jimmy Howard) the other night was super sharp so both goalies have done a good job of getting themselves ready and they both look like they're in a good spot right now."
With four games in four nights coming up Wednesday-Saturday, that will give the Wings a chance to play Calvin Pickard and Filip Larsson.
"My No. 1 goal is to make sure Jimmy and Jonathan are ready to roll come Day 1," Blashill said. "That's just the reality of the spot that we're in. We'll get the other two a little bit more playing time in one of these two games before they're done but our goal is three and a half for each of those other guys. That's our No. 1 goal."