...Tangradi was experiencing concussion-like symptoms after absorbing an elbow from Islanders left wing Trevor Gillies early in the third period.
— Source: TribLive: Sports
Bylsma also references Tangradi's condition at the top of his interview, here:
(This link starts the most recent post-game video- most likely Staal's. You might have to navigate to Bylsma's on that page yourself.)
Postgame: Dan Bylsma