The 33-year-old Wada joins the Cubs for the second time this season, as he made his big league debut July 8 at Cincinnati and recorded a no-decision after allowing one unearned run on five hits and a walk in 5.0 innings, striking out three. He returned to Iowa after the game. Wada was named to the Pacific Coast League All-Star team and is 10-6 with a 2.77 ERA (35 ER/113.2 IP) in 19 appearances (18 starts) with Iowa this season. The southpaw signed a minor league contract with the Cubs this past offseason and was added to the 40-man roster on June 22.
Following a nine-year career with the Fukuoka Softbank Hawks in the Japan Pacific League, Wada signed a two-year major league deal with Baltimore in December of 2011. He suffered an elbow injury during Spring Training of 2012 that led to Tommy John ligament replacement surgery in May. He returned to action in June of 2013, and made 19 starts for Triple-A Norfolk last season, going 5-6 with a 4.03 ERA (46 ER/102.2 IP).
Wada went 107-61 with a 3.13 ERA (503 ER/1,444.2 IP) in 210 games, all but three as a starter, for Fukuoka from 2003-11, striking out 1,329 batters while walking just 395. He recorded 36 complete games, including eight shutouts, and was named the league's Most Valuable Player in 2010, a season in which he was 17-8 with a 3.14 ERA (59 ER/169.1 IP) in 26 starts.
Olt, 25, had been with the big league club since Opening Day and is batting .139 (26-for-187) with 12 home runs and 30 RBI in 72 games with the Cubs this season.