The Mariners have already said they would make the offer, meaning the team will receive draft pick compensation if Morales signs elsewhere.
Seattle has made overtures to Morales recently about a contract extension, but this close to free agency he has instead decided to see what he can get on the open market. Along with Mike Napoli, he is arguably one of the top two first baseman available this offseason with Mike Morse, Justin Morneau, Paul Konerko and Kevin Youkilis in the second tier.
Morales played 156 games for the Mariners in 2013 after being acquired in a trade with the Angels last offseason. He hit .277/.336/.449 with 23 home runs. He spent most of his time at DH, but is fully capable of playing first base.
A return to Seattle remains possible, but the Mariners will now have to compete with 29 other clubs for his services.