ARLINGTON -- The Rangers acquired their first new candidate for the starting rotation when they traded for right-handed pitcher Ronald Herrera from the Yankees and added him to their 40-man roster. In exchange, the Rangers gave up Minor League lefty Reiver Sanmartin.
The Rangers also added six Minor League players to their 40-man roster: right-handed pitchers Jonathan Hernandez and Ariel Jurado, left-handed pitchers Brett Martin and Joe Palumbo, catcher Jose Trevino and utility player Isiah Kiner-Falefa. All six were eligible to be taken in the Rule 5 Draft if not protected.
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Herrera, 22, began the 2017 season by going 8-1 with a 1.91 ERA in 14 starts for Double-A Trenton. He also made two relief appearances with the Yankees in June, allowing two runs in three innings.
He spent the final two months at Triple-A Scranton/Wilkes-Barre but made just two starts while dealing with shoulder inflammation. He was able to make one start for the team in the postseason, however, and the Rangers expect him to be at full strength in Spring Training.
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Herrera, listed at 5-foot-11 and 185 pounds, is a four-pitch pitcher with a fastball that averages 91.7 mph and a plus changeup.
"We see him as starting pitcher, a 22-year old who got a big league look," Rangers general manager Jon Daniels said. "He had some shoulder inflammation but came back strong. He is a strike-thrower who knows how to pitch. The sum is greater than the parts."
Herrera was originally signed by the Athletics in 2011 before being traded to the Padres in 2014 and the Yankees in 2015. The Yankees traded him because they had no room for him on their 40-man roster.
"He is an undersized right-handed pitcher," Daniels said. "As you make decisions and calls on who to protect, he always had that going against him. But every step through the Minors, he has done the same thing, mixed his pitches and thrown a lot of strikes. The Yankees have a lot of good players and had to make some tough decisions. This was a good swap for us."
Herrera will join Jurado, Hernandez and Martin among the young pitchers who will get a look in Spring Training.
Jurado, a hard-throwing sinkerball pitcher who is the ninth-ranked prospect in the Rangers' system according to MLBpipeline.com, was 9-11 with a 4.59 ERA in 27 starts at Double-A Frisco. He averaged 5.4 strikeouts, 2.1 walks and 10.8 hits per nine innings.

Hernandez, who represented the Rangers in the 2017 All-Star Futures Game and is ranked No. 21 in the system, split time between Class A Hickory and Class A Advanced Down East. In 23 games, he was 5-11 with a 4.03 ERA, averaging 8.9 strikeouts, 3.5 walks and 9.8 hits per nine innings.
Martin made 16 starts for Down East and was 4-8 with a 4.70 ERA, averaging 9.6 strikeouts, 3.7 walks and 10.0 hits per nine innings. He is ranked as the No. 10 prospect in the Rangers' system by MLBpipeline.
Palumbo was a rising star in the Rangers' system and began the year by going 1-0 with a 0.66 ERA in three starts for Down East before undergoing Tommy John surgery. He is still ranked No. 12 in the system and is on pace to return in June.

Trevino is the No. 13 prospect in the Rangers' system and spent all of the '17 season at Double-A Frisco. He hit .242 with seven home runs and 42 RBIs in 105 games while earning his second straight Minor League Gold Glove for defensive excellence.
Kiner-Falefa is not ranked among the Rangers' top 30 prospects but has risen fast through the system after being taken in the fourth round of the 2013 MLB Draft out of Mid-Pacific Institute (in Hawaii). Kiner-Falefa batted .288 with 31 doubles, three triples, five home runs, and 48 RBIs over 129 games with Frisco. He also played second base, third base, shortstop, center field and a career-high 33 games at catcher.