A depleted blue line could catch up to the Gophers on Friday night.

They are without defensemen Ben Marshall and Michael Brodzinski, and Jake Parenteau will play just his second game in nearly two months. That leaves four defensemen to carry most of the load against Michigan State on Friday night at 8 p.m.

The last time the Gophers played with a depleted defensive core they tied an under-.500 Colgate team at the time.

Throughout the week of practice, usual forwards A.J. Michaelson , Gabe Guertler and Ryan Reilly suited up as defensemen. Michaelson got the nod for the sixth defenseman on Friday night, but likely won't spend much time, if any, on the blue line.

Gophers coach Don Lucia used the trio to help give the regular defensemen more rest. They'll be expected to spend extra time on the ice against the Spartans.

Marshall was suspended one game for collecting three game misconduct penalties in the same season. Brodzinski sustained a lower-body injury, last Friday. Lucia said Brodzinski likely won't return until the last week of February.

The Gophers are also without senior forward Tom Serratore. He is expected to miss a couple weeks after blocking a shot in last weekend's North Star College Cup championship game.

More on injuries and mid-week video.

• Christian Horn won't be returning to the Gophers.

The forward announced on Twitter earlier this week he had committed to St. Lawrence University (Canton, N.Y.). The Saints play in the Eastern Collegiate Athletic Conference.

Horn, a Benilde-St. Margaret's product, left the Gophers in late October for more playing time in the USHL. He became the Tri-City Storm's leading scorer with 25 points (12 goals, 13 assists) and earned a plus-five rating in 28 games.

The impressive season attracted the attention of not just St. Lawrence, but the USHL's Sioux Falls Stampede. They acquired Horn this week from the Storm in exchange for a draft pick and swap of future players.

After Horn's departure, Lucia said he'd be open to have the sophomore return after his season away. That option is no longer a possibility.

For more on Horn's departure from the Gophers including video from Lucia, see the original blog post.

• SERIES PREVIEW: MICHIGAN STATE (8-12-3 overall, 2-4-2-2 Big Ten) at NO. 1 GOPHERS (18-2-4, 7-0-1-0)

8:04 p.m. on Friday and 7:10 p.m. on Saturday at Mariucci Arena

TV/radio/live stream: BTN on Friday and FSN-plus on Saturday; 1500-AM both nights; BTN2Go.com both nights

Gophers at a glance: The Gophers return to Big Ten play shorthanded. Defenseman Ben Marshall was suspended one game for collecting three game misconduct penalties in the same season. Forward Tom Serratore and defenseman Michael Brodzinski sustained lower-body injuries and will be sidelined at least two weeks. The last time the Gophers were in a similar situation they tied Colgate in their first game back from winter break. They do, however, hold a 12-game unbeaten streak.

Spartans at a glance: Michigan State is coming off a pair of losses to rival Michigan, but is 2-2-1 over its last five games. The Spartans tied and lost a one-goal game to the Gophers in the first half of the round-robin conference schedule in East Lansing, Mich. Like the Gophers, the Spartans play a lot of sophomores and freshmen. Coach Tom Anastos said the group is starting to play with more confidence and succeed in the right line combinations.

• Read Friday's feature: College hockey's focus lands on hits to the head.Chart and video.

• Gophers lines
Forwards (left wing, center, right wing)
Sam Warning, Kyle Rau, Hudson Fasching
Nate Condon, Justin Kloos, Taylor Cammarata
Connor Reilly, Travis Boyd, Seth Ambroz
Ryan Reilly, Christian Isackson, Vinni Lettieri

Defensemen (left, right)
Brady Skjei, Justin Holl
Mike Reilly, Jake Parenteau
A.J. Michaelson, Jake Bischoff

Goaltenders
Adam Wilcox, Michael Shibrowski, Ryan Coyne