Keith played 41 games for MSU during the 2001-02 season, tallying 15 points (3-12–15) as a freshman. He played alongside former defenseman and current MSU Director of Player Development Brad Fast. 

Keith was drafted to the Chicago Blackhawks in the second round of 2002, but returned to MSU for 15 games, collecting nine points (3-6–9) before heading to the Western Hockey League. During Keith's final season at MSU he was teammates with current Spartan coach Adam Nightingale. 

"I remember how committed he was," Nightingale said. "That was so obvious when I got here as a player, like, his commitment level to being an elite player, and it took him some time for sure right here, and that's that position a little bit. But what an honor."

Throughout 37 games Keith developed in the WHL, notching 11 goals and 35 assists (11-35–46). He made his NHL debut for the Blackhawks in 2005, where he spent the majority of his career — some of Chicago’s best years. Keith won the Stanley Cup with Chicago in 2010, 2013 and 2015, scoring the cup-winning goal and winning the Conn Smythe Trophy. No other team has won the title three times within six seasons since the Blackhawks. 

Keith’s NHL career embodies the brand of hockey that Nightingale is trying to instill in the Spartans — blue collar, long-term goal, consistent hockey.

"He was a guy that was, you know, a team guy," Nightingale said. "A do-it-the-right-way guy, super committed guy. I think a lot of the things that I want our guys to be as players and people Duncan (Keith) represents."

Keith played 1,192 games in the Blackhawks jersey, more than any other Chicago defenseman and the second most of any Blackhawk. He sits sixth overall in assists (520) and tenth overall in points (625). He finished his career (106-540–646) with the Edmonton Oilers during the 2021-2022 season.