Baker said the procedure will take place Wednesday in Texas. Ross, who will miss the remainder of the season, was placed on the 10-day disabled list with a strained right triceps on Friday.
The 24-year-old owns a 5-3 mark with a 5.01 ERA in 13 starts this season. He posted a 2-1 record with a 2.36 ERA in four outings prior to sustaining the injury.
Ross sports a career 17-13 record and 3.95 ERA in three seasons with Washington.
--Kansas City Royals right-hander Nate Karns will undergo season-ending surgery next week to remove a rib that's causing nerve pain in his forearm, the team announced.
The thoracic outlet surgery will be performed by Dr. Gregory Pearl on Wednesday in Dallas, according to a report by MLB.com. Thoracic outlet syndrome is caused by compression of nerves, arteries or veins in the area between the lower neck and armpit area.
Karns was off to a promising start in his first season with Kansas City, posting a 2-2 mark with a 4.17 ERA. The 29-year-old was placed on the disabled list May 21.
--The Boston Red Sox placed right-hander Joe Kelly on the 10-day disabled list with a left hamstring strain.
Kelly felt the strain before the All-Star break and took a few days off, but he still felt it on Saturday. The move is retroactive to July 12. To fill Kelly's spot on the 25-man roster, the Red Sox recalled right-hander Brandon Workman from Triple-A Pawtucket.
Kelly, 29, is 3-1 with a 1.49 ERA over 36 1/3 innings and a .189 opponent batting average this season, recording 26 strikeouts against 16 walks in 34 appearances. He has a 0.78 ERA over 23 innings in his last 24 outings, having made a career-best 23 consecutive scoreless appearances from May 1-July 3.
Workman, 28, has made two major league appearances over three stints this season, allowing two earned runs over 5 1/3 innings with four strikeouts and one walk.
Castro suffered a strained right hamstring while running out a ground ball on June 26. He returned to the starting lineup in Boston on Saturday, batting fifth.
Castro, 27, is batting .313 with 12 home runs and 45 RBIs in 73 games this season. The Yankees went 4-9 in 13 games with Castro on the DL.
To make room on the roster, the Yankees optioned infielder/outfielder Tyler Wade to Triple-A Scranton/Wilkes-Barre.
--The St. Louis Cardinals placed right fielder Stephen Piscotty on the 10-day disabled list because of a right groin strain.
The Cardinals also recalled rookie outfielder Magneuris Sierra from Triple-A Springfield prior to Saturday night's game against the Pittsburgh Pirates,
Piscotty, 26, injured his right groin on Friday night in the ninth inning after running to catch a shallow fly ball, forcing him to leave the game.
Piscotty is making his second appearance on the disabled list this season, as he missed 12 games from May 5-19 because of a strained right hamstring. He is batting .236 with six home runs and 31 RBIs in 69 games this season.
Colon was picked up by the Twins after the 44-year-old was released by the Atlanta Braves. The former American League Cy Young Award winner made one start with Triple-A Rochester, allowing four earned runs on as many hits in 3 2/3 innings against Lehigh Valley.
Mauer, who had been sidelined since July 7 with a strained lower back, was expected to bat third in the lineup against the Houston Astros on Saturday. Buxton exited Friday's 10-5 loss to the Astros in the sixth inning with left groin soreness.
Yrizarri, 20, is batting .258 with seven home runs and 37 RBIs in 82 games between High Class A Down East and Class A Hickory this season.
Yrizarri has appeared in 331 career games over four minor league seasons in the Rangers' farm system, hitting .262 with 17 home runs and 148 RBIs.