Yesterday was the deadline for teams to tender arbitration-eligible players. In more natural terms, that means yesterday was the last chance for teams to decide they would bring back players without contracts, and without enough service time to walk away in free agency.
Even that last statement doesn't make a whole lot of sense, because non-tendered players become free agents. Some people say baseball's roster rules are excessively complex. I say they are just complex enough to be amusing.
The Mariners did not make any huge moves, but each is worth a few thoughts.