After appearing in ten games in '09, Moscoso had an ERA of 3.21 through 14.0 innings pitched, giving up 15 hits, 7 runs, and 6 walks but also struck out a dozen. As of August, Moscoso has only pitched one game in the new decade. On May 20, against Baltimore, Guillermo pitched 2⁄3 of an inning, giving up two hits, two runs, and two walks while also striking out two. His ERA is currently 27.00.
Oakland Athletics
In January 2011, Texas traded Moscoso to the Oakland for Ryan Kelly.[3]
On May 24, 2011, he was recalled to the Oakland Athletics to take the place in the rotation of Tyson Ross, who went on the DL with a strained left oblique. Fautino de los Santos was optioned to Triple-A to make room.[4]
On September 7, 2011, he carried a no hitter against the Kansas City Royals into the eighth inning.
Colorado Rockies
On January 16, 2012, Moscoso was traded, along with fellow pitcher Josh Outman, to the Colorado Rockies for outfielderSeth Smith.[5] Moscoso went 3–2 with a 6.12 ERA with 50 innings in 23 appearances, 3 starts.
Kansas City Royals
The Kansas City Royals claimed Moscoso off waivers on November 2, 2012.[6] The Royals released him on March 13, 2013.[7]
Toronto Blue Jays
The Toronto Blue Jays announced that they had claimed Moscoso on waivers on March 16, 2013.[8]
Chicago Cubs
On March 27, 2013, Moscoso was claimed on waivers by the Chicago Cubs.
San Francisco Giants
On July 26, 2013, Moscoso was traded to the San Francisco Giants for a player to be named later or cash considerations.[9] He was designated for assignment on November 20, 2013. On November 21, 2013, Moscoso elected to become a Free Agent.
On May 7, 2017, Moscoso signed with the Bravos de León of the Mexican Baseball League. In 16 games 15 starts he threw 88 innings and went 7–3 with a 3.89 era with 24 walks and 60 strikeouts.
Los Angeles Dodgers
On February 7, 2018, Moscoso signed a minor league deal with the Los Angeles Dodgers. He appeared in 16 games (13 starts) for the AAA Oklahoma City Dodgers with a 4.90 ERA. He was released on June 29, 2018.
Bravos de León (second stint)
On July 3, 2018, Moscoso signed with the Bravos de León of the Mexican League. He became a free agent following the season, but later re-signed with the team on April 23, 2019.
Pericos de Puebla
On July 2, 2019, Moscoso was traded to the Pericos de Puebla of the Mexican League. In 11 games (10 starts) he went 2–4 with a 6.15 era across 52.2 innings with 14 walks and 32 strikeouts.
On December 20, 2021, Moscoso re-signed with the Bravos de León of the Mexican League for the 2022 season.[11] He made 9 starts for the club and went 1–5 with a 8.47 ERA and 27 strikeouts. Moscoso became a free agent following the season.
Pitching style
Moscoso throws three main pitches: a four-seam fastball (90–92), a curveball (77–79), and a changeup to left-handed hitters (80–81). He has experimented with a cut fastball and slider to right-handers, but he does not use them frequently.[12]
After he went to Japan, he learned a two-seam fastball.