Witherspoon, 24, spent last season at double-A Arkansas where he stole 30 bases in 129 games. He has 140 steals (33 caught stealing) in his minor league career, including a combined 110 steals since the start of the 2011 season.
The right-hand-throwing, right-hand-hitting outfielder is 6-foot-2, 190 pounds. Last year was Witherspoon's first full season at AA, and he hit .214 with 18 doubles, 3 triples, 11 home runs and 38 RBI to go with 55 walks and 30 steals.
In 2012, he split the season between Inland Empire (A) and Arkansas, batting a combined .268 with 80 runs, 13 homers, 48 RBI and 34 steals. He was a mid-season Cal League All-Star, and participated in the Arizona Fall League following the season.
Witherspoon was selected by the Angels in the 12th round of the 2009 June Draft out of Spartanburg Methodist College in South Carolina. He graduated from Sumter High School in Sumter, SC.
Blanco, 42, hit .125 (12x96) with 8 runs scored 2 doubles, 3 home runs and 14 RBI in 35 games with the Mariners after being signing as a Major League free agent on June 14. He also appeared in 15 games with the Blue Jays to begin the season, catching in 13 games, including 11 consecutive starts by knuckleballer R.A. Dickey. Blanco is a veteran of 16 Major League seasons with Los Angeles (NL, 1997), Colorado (1999), Milwaukee (2000-2001), Atlanta (2002-2003), Minnesota (2004), Chicago (NL, 2005-2008), San Diego (2009), New York (NL, 2010), Arizona (2011-2012), Toronto (2013) and Seattle (2013).