I read two reports that seem to indicate that Jack Leavy came on to relieve Portillo with no mention of injury or anything else regarding Portillo. Perhaps this was planned?
Michigan Daily:
"Sophomore goaltender Erik Portillo saved 17 shots in 41 minutes of action. Portillo, along with a stout performance from his blueliners, held Bowling Green scoreless for most of the game. Senior goaltender Jack Leavy relived Portillo and shortly gave up a rebound goal. Aside from that, however, the back end was difficult to penetrate."
Note - the box score showed 19 saves in 51 minutes. Maybe the reporter had to take a dump and missed some action
MGoBlue.com:
"Fans.... were treated to an offensive display from the opening whistle, while sophomore netminder Erik Portillo was sturdy in net, turning aside 17 shots to pitch a shutout in his two and a half periods of play."
"Goaltender Jack Leavy came on in relief of Portillo after the halfway point of the third period. Bowling Green got on the board to make it 7-1 with 5:38 left to play when Coale Norris, brother of former Wolverine, Josh, pounced on a bouncing puck in front of Leavy and buried a rebound."
Box score on Portillo 19 saves (6/9/4), 0 GA, 51 minutes
Looks like both reporters needed to shake off some preseason cobwebs