The Texas Rangers placed right-handed reliever Jacob Webb (back spasms) on the 15-day injured list on Wednesday, retroactive to July 29, and promoted right-handed reliever Luis Curvelo from Triple-A Round Rock. Webb, 31, worked 1 2/3 innings in relief Monday in Los Angeles, allowing one earned run with a season-high four strikeouts versus the Angels. He has a 4-3 record with a 3.75 ERA in 48 innings over 42 relief appearances this season for Texas, his first with the club after signing a one-year contract on Dec. 11. His 48 innings rank second among Rangers relievers behind Hoby Milner’s 49.2. Curvelo, 24, is on the Rangers’ active roster for the first time and his first appearance will serve