The Mariners have signed outfielder Wily Mo Pena to a Minor League contract, the club announced Wednesday.Pena is scheduled to report to the Mariners' Minor League complex in Peoria, Ariz., and will soon join Triple-A Tacoma. The 29-year-old split this season between the D-backs and Triple-A Reno before Arizona designated him for assignment on July 15. He hit .196 with five home runs and seven RBIs in 17 games for the D-backs this season. Before being called up to the Majors, Pena was hitting .363 with 17 doubles, 21 home runs and 63 RBIs in 63 games at Triple-A. Pena has spent parts of eight seasons in the Majors with the Reds, Red Sox, Nationals and D-backs. He is a career .251 hitter with 82 home runs and 232 RBIs in 577 games.