Per SB Nation's Chris Cotillo, Ross signed a minor league deal with the team.
Ross has fallen on hard times since the start of 2016. The 30-year-old made just one start for the Padres in that season after suffering a shoulder injury.
San Diego decided to non-tender Ross last offseason, making him a free agent, and the Rangers took a chance on him.
Things didn't work out for Ross in 2017. The right-hander spent time on the 60-day disabled list before returning to Texas' rotation on June 16. He posted a 7.71 ERA with more walks (37) than strikeouts (36) in 49 innings.
At his peak from 2013-15, Ross showed the ability to be a strikeout artiest. He wasn't much of a strikeout pitcher in Oakland (102 in 148.2 innings), but he averaged 9.2 punchouts per nine innings in four seasons with the Padres.
Ross was effectively wild at his best, as he walked 116 hitters in 320.2 innings in 2013-14. He was more erratic in 2015 with a league-leading 84 free passes.
One reason for Ross' past success, particularly in 2015, was his ability to limit hard contact, per Daren Willman of BaseballSavant.com:
Daren Willman @darenw
Pitchers giving up fewest % of 100 MPH+ batted balls Kershaw 9.4% Harvey 10.4 Tyson Ross 10.6 Arrieta 11.1 Sale 11.2 http://t.co/Pd01CdJ8t72015-7-6 15:01:54
The Padres need depth in their starting rotation after finishing 23rd in MLB with a 4.83 ERA last season. Ross is a low-cost, high-reward investment for the team that knows him better than anyone else.