The Mariners have acquired Michael Morse from the Nationals in a three-team trade.

Oakland landed John Jaso in the agreement.

Washington reacquired pitching prospect A.J. Cole, dealt to Oakland 13 months ago in the trade for Gio Gonzalez. The Nationals also got minor league pitcher Blake Treinen and a player to be named.

Morse was with the Mariners from 2005-08 before he was traded to the Nationals for Ryan Langerhans in June 2009.

"I'm just glad this whole thing has unfolded the way it has," Morse said on a conference call, noting he was aware he might be traded by Washington.