Seniors took to Twitter shortly after the announcement to vent their feelings, question Penn State's choice, and voice their collective frustrations.
Hippenhammer, who opted to focus on baseball full-time this spring, is reportedly in the NCAA's transfer portal.
"We've got a bunch of other good linebackers, guys I'm really excited about. When you lose guys like Jan [Johnson] and Cam [Brown], they're tough to replace, but I like the guys in the room."
"There are a lot bigger things going on in the world than Penn State hockey, but I really do feel for this team. They were really hungry to prove we could go far in the NCAA tournament."
The Nittany Lion will face Pitt's Roc the Panther in the first round.
According to University Tees, a percentage of the proceeds from the apparel sale will be donated to the State College food bank "to help support the State College community in this difficult time."