An intentional ball is where the pitcher purposely throws a pitch out of the strike zone with the purpose of walking the hitter so they can pitch to another hitter.
It is usually a play on percentages, and where the team feels that they have a better chance of getting the other hitter out.
Ryan Franklin is a tall Rangy guy who is a step above mediocre. He won't get you killed but don't expect Randy Johnson out there. M's have plenty of offense. In games like this where Boston keeps squandering opportunities it usually comes back to haunt them in late games.