Ruben "R.J." Alaniz (born June 14, 1991) is an American professional baseball pitcher for the Acereros de Monclova of the Mexican League. He has previously played in Major League Baseball (MLB) for the Seattle Mariners and Cincinnati Reds.
Alaniz was born in McAllen, Texas and attended Juarez-Lincoln High School in La Joya, Texas.
He was signed as an undrafted free agent by the Houston Astros on August 14, 2009, after participating in a tryout camp run by scout Rusty Pendergrass. He was signed for $160,000, with Pendergrass and scout Clarence Johns claiming Alaniz has the "stuff to be a major league starter." He began his professional career the next year. With the Greeneville Astros in 2010, he was 6âÂÂ4 with a 4.21 ERA and the following year, he was 7âÂÂ10 with a 4.44 mark for the Lexington Legends. In 2012, Alaniz went 6âÂÂ2 with a 5.04 ERA for the Lancaster JetHawks and in 2013, he was 9âÂÂ9 with a 4.53 mark for the Corpus Christi Hooks. He was 1âÂÂ1 with a 6.64 ERA for the Corpus Christi Hooks in 2014 before being suspended 50 games for using a drug of abuse in late August. It was his second suspension. Alaniz was once rated as having the best curveball in the Astros system and had been named among the club's best prospects. He appeared in major league spring training in 2012. He returned in 2015 to go 6âÂÂ4 with a 4.55 ERA for the Hooks. he became a free agent following the season
Alaniz signed a minor league contract with the Detroit Tigers organization on December 3, 2015. He split the 2016 season between the Erie SeaWolves and the Toledo Mud Hens, accumulating a 4âÂÂ4 record with a 2.69 ERA in 73 innings. In 2017, he again split the year between Erie and Toledo, accumulating a 3âÂÂ3 record with a 2.30 ERA in innings. He elected free agency following the season on November 6, 2017.
On December 14, 2017, Alaniz signed a minor league contract with the Tampa Bay Rays organization. He split the 2018 season between the rookieâÂÂlevel GCL Rays, the HighâÂÂA Charlotte Stone Crabs, the DoubleâÂÂA Montgomery Biscuits, and the TripleâÂÂA Durham Bulls. He accumulated a 3âÂÂ4 record with a 3.38 ERA in innings. Alaniz elected free agency following the season on November 2.
On November 15, 2018, Alaniz signed a major league contract with the Seattle Mariners. He opened the 2019 season with the Tacoma Rainiers.
On April 12, 2019, he was recalled to the major leagues for the first time. He made his debut that night, allowing four runs over two innings of relief. In 4 games with Seattle, Alaniz struggled to a 20.25 ERA.
On May 31, 2019, he was claimed off waivers by the Cincinnati Reds and optioned to the Louisville Bats. Alaniz recorded a 5.40 ERA in 8 games with Reds. On December 9, Alaniz was outrighted off the Reds 40-man roster.
On September 15, 2020, Alaniz was selected to the major league roster. Alaniz did not make an appearance for Cincinnati in 2020 and was non-tendered by the Reds on December 2. On December 11, Alaniz re-signed with the Reds on a minor league contract. He was assigned to Louisville to begin the 2021 season and posted a 2.25 ERA in 21 appearances. On July 19, 2021, Alaniz was selected to the active roster. In 3 appearances for the Reds in 2021, Alaniz posted a 3.38 ERA with 3 strikeouts. On September 22, 2021, the Reds designated Alaniz for assignment. On October 6, Alaniz elected free agency.
On January 24, 2022, Alaniz signed with the Acereros de Monclova of the Mexican League for the 2022 season. Prior to the start of the Mexican League season, on March 20, Alaniz signed a minor league contract with the Atlanta Braves organization. In 20 games for the Triple-A Gwinnett Stripers, Alaniz logged a 3âÂÂ1 record and 3.81 ERA with 41 strikeouts in 26.0 innings of work. He elected free agency on November 10.
On February 3, 2023, Alaniz signed with the Acereros de Monclova of the Mexican League. In 23 relief outings, he posted a 4.01 ERA with 20 strikeouts and one save across innings of work.
Alaniz made 35 appearances for Monclova in 2024, posting a 4âÂÂ3 record and 2.31 ERA with 39 strikeouts and 10 saves across 35 innings of relief.
Alaniz re-signed with Monclova for the 2025 season his third with the team. He finished the season having appeared in 28 relief appearances, posting a 3-0 record and 4.05 ERA with 41 strikeouts and 12 saves.