Texas will make a corresponding move on its active roster before Thursday's game in New York.
Knebel (pronounced kuh-NAY-buhl), 22, has posted no record in 8 relief appearances for Detroit this season, his first major league action, allowing 7 runs (6 earned) in 8.2 innings. He was recalled from Triple-A Toledo for a second stint with Detroit on Saturday, July 19, and was also with the Tigers from May 23-June 14. His major league debut came against the Rangers on May 24 in Detroit. He has spent the rest of the season with Erie (AA) and Toledo, going a combined 4-1 with a 1.62 ERA (6 ER/33.1 IP) and 3 saves over 25 relief appearances. Knebel owns a career 0.855 WHIP figure in 56 minor league outings, averaging 11.8 strikeouts per 9 innings. A first round selection (Competitive Balance Round A) by Detroit in the 2013 June Draft, Knebel was born in Denton and graduated from Georgetown High School before pitching for the University of Texas at Austin. He was signed by Tigers scout Tim Grieve, son of Rangers Hall of Famer Tom Grieve.
Thompson, 20, has gone 7-4 with a 3.06 ERA (32 ER/94.0 IP) in 18 games/starts for Lakeland (High-A) and Erie (AA) this season. He was recently promoted for his first action at Double-A and has gone 1-0 with a 2.45 ERA (3 ER/11.0 IP) in 2 starts, including a win tonight against Reading (5.0 IP, 1 R-ER). Thompson has 208 strikeouts over 205.2 innings in the minor leagues. He was selected in the second round of the 2012 June Draft out of Rockwall-Heath High School, which is east of Dallas, and was also signed by Tim Grieve.
Soria is 1-3 with a 2.70 ERA and 17 saves in 35 appearances with the Rangers this season. He was signed as a free agent prior to the 2013 season and was 1-0 with a 3.80 ERA in 26 games a year ago after completing his rehab from Tommy John surgery in April 2012.
With tonight's moves, the Rangers' major league roster remains at 40 players.