Marté signed with the Seattle Mariners as an international free agent on August 13, 2010. He made his professional debut in 2011 for the Dominican Summer League Mariners. He played 2012 with the Everett AquaSox and Clinton LumberKings.
Marté spent 2013 with Clinton and the High Desert Mavericks. He hit .295 with a .687 on-base plus slugging (OPS). Marté started 2014 with the Double-A Jackson Generals and was promoted to the Triple-A Tacoma Rainiers during the season.
He finished the season hitting .304 with a .746 OPS and four home runs. On November 20, 2014 Ketel was placed on the 40–man roster. The Mariners promoted Marté to the major leagues on July 31, 2015.