If Iwakuma does get the $15.8 million qualifying offer, that doesn't guarantee he'll remain with the Mariners. All 34 Major Leaguers who received qualifying offers from 2012-14 turned them down and became free agents.
If Iwakuma rejects the offer, the Mariners still will attempt to sign him to a multiyear deal, though they'll be competing with MLB's other 29 teams at that point. If Iwakuma then signs with another club, the Mariners would receive an extra Draft pick as compensation.
But Dipoto said Karns' addition had nothing to do with any of that.
"I don't think we had a complete starting rotation to begin with," he said.