Let’s get this part out of the way first: there has been no real indication from the Mariners that they are trying to trade for a third baseman. That matters, because this is how these things get sideways fast. One struggling team has expensive contracts. Another team has a lineup that could always use more offense. Social media looks at the two rosters, sees a recognizable name, and suddenly we’re talking ourselves into a trade fit that sounds a lot cleaner in theory than it does once we actually put it on the board.

The Giants have become one of the more interesting teams to watch for uncomfortable reasons. Their long-term contracts are weighing heavy on them.…