Hits happen in the middle of the ice all the time and Johnny Gaudreau is too experienced of a player to be making mistakes like this. It's unfortunate as it looks like both players didn't mean to collide like that, and it resulted in Gaudreau with a possible injury. Gaudreau left the game after the collision but has since returned for the third, so hopefully he was able to avoid an injury.
The play was reviewed for a 5 minute major on Trocheck, but it was found that he didn't commit any infraction on the play. This is definitely the right call as Trocheck didn't try to hit Gaudreau, it was just a collision of the two. Players need to be more aware when carrying the puck through the middle of the ice, and there has been a scary amount of injuries as a result.