DENVER -- The Rockies completed a deal with the Blue Jays on Thursday to acquire right-hander Seunghwan Oh to bolster their bullpen for a pair of prospects who were ranked on the organization's Top 30 Prospects list. 
The Rockies sent outfielder Forrest Wall, a first-round pick in the 2014 MLB Draft and their No. 13 prospect; first baseman Chad Spanberger, a sixth-round Draft pick in '17 and the No. 24 prospect, and a player to be named or cash to Toronto.
Oh, 36, pitched in Korea and Japan before joining the Cardinals in 2016. Entering Tuesday, he ranked fifth in the American League with 48 appearances this season. Oh is 4-3 with a 2.68 ERA, two saves, 55 strikeouts and 10 walks in 47 innings.
Oh went 7-9 with a 2.85 ERA with the Cardinals from 2016-17. He is making $1.75 million this season and has a $2.5 million club option for 2019 that can automatically vest if he reaches 70 appearances. Additionally, Oh's contract is under club control through 2021.
Colorado's bullpen has shown improvement after struggling for much of June. From June 26 to Tuesday's 8-2, 10-inning loss to the Astros, the relief staff has had a 4.10 ERA -- but in the 15 wins during that period its ERA was 2.66. However, the Rockies needed to beef up the group.
They've relied heavily on righty setup men Scott Oberg and Adam Ottavino, as well as closer Wade Davis. While righty Bryan Shaw, who struggled early, has shown improvement since returning from a right calf strain, the Rockies still needed depth.
Also, the left side of the 'pen has struggled. Jake McGee and Chris Rusin have lacked consistency, and Rusin went to the 10-day disabled list Tuesday with right foot plantar fasciitis.
Oh's closing experience is impressive -- he had 19 saves in 2016 and 20 in '17 with the Cardinals.
This season, Oh's slash line has been far more impressive against right-handed batters (.168/.190/.269) than lefties (.315/.413/.537). His career numbers are just as strong against righties (208/.242/.316), but not as lopsided against lefties (.257/.328/.415)
Wall, 22, who was drafted out of Orangewood Christian High School in Maitland, Fla., was selected as an infielder, but has transitioned to the outfield. He was hitting a combined .260 with nine homers and 31 RBIs with 28 stolen bases in 39 attempts for Class A Lancaster and Double-A Hartford. Picked as an infielder who had suffered a shoulder injury in high school, Wall moved to the outfield as the Rockies attempted to take advantage of his speed.
Spanberger, who is also 22, was drafted out of the University of Arkansas. He was hitting .316 with 22 home runs and 75 RBIs for Class A Asheville. Last year, he hit .294 with 19 home runs in 60 games at Rookie-level Grand Junction.
Earlier reports had first baseman Sean Bouchard, also playing first base at Asheville, in the deal. But Bouchard participated -- and hit a home run -- in the second game of a doubleheader on Wednesday night, which was a clear indication he wasn't in the trade. Players who are dealt are usually removed from their game for fear of an injury scuttling all the negotiations.
Casilla agrees on Minor League deal
The Rockies and veteran right-handed reliever Santiago Casilla have agreed to terms on a Minor League contract, the club confirmed. The Athletic first reported the agreement.
Casilla, 38, had a 3.16 ERA in 26 games with the Athletics earlier this season before being designated for assignment July 14. He struck out 22 but walked 20 in 31 1/3 innings pitched.
Casilla, 38, has pitched in 15 seasons for the Athletics (2004-09, 2017-18) and Giants (2010-16).
Casilla will pitch at Triple-A Albuquerque and serve as right-handed depth.