If you have enough time, find parking on Commercial St. down by the harbor. It will give you a nice walk to and from the stadium.

Driving is definitely the most expensive option to get to the game unless you can get a spot on the street. I would recommend using public transportation or an uber unless you feel confident you can find a spot on the street and feed the meter until 8pm.

There is limited amounts of parking and it is quite expensive. You can save a little money and walk a mile or so but I would suggest taking the T.