Toronto Blue Jays starter Ryu Hyun-jin pitches against the Baltimore Orioles during the top of the first inning of a Major League Baseball regular season game at Rogers Centre in Toronto on Tuesday. (Yonhap)

Ryu Hyun-jin of the Toronto Blue Jays struggled in his first major league start in 14 months, constantly pitching with traffic on the bases against a division rival.

Ryu took the loss in the Orioles' 13-3 rout of the Blue Jays at Rogers Centre in Toronto on Tuesday (local time), after giving up four runs on nine hits in five innings. Ryu left the game with the Orioles leading 4-3 following Gunnar Henderson's solo shot to begin the top of the sixth. The bullpen coughed up nine runs over the next three innings.

This was Ryu's first start since June 1 last year. He underwent Tommy John surgery to repair ligament damage later that month, the second time he has required that operation in his career.

With Ryu's return, the Blue Jays will be running a six-man rotation, as they're in the midst of a tough stretch of 17 games in 17 days.

Ryu gave up a run after only four pitches into his outing. Leadoff man Adley Rutschman jumped on Ryu's first-pitch fastball for a double off the right-center field wall. Then Ryan Mountcastle hit a double to left-center on a third-pitch cutter for a 1-0 Orioles lead.

Anthony Santander's single put runners at the corners, and a fielder's choice grounder by Henderson brought in Mountcastle to put the O's up 2-0.

Ryu escaped the inning with his first strikeout of the day, as Jordan Westburg fanned on a high changeup.

The Orioles opened the second inning with another double, this time off the bat of Ramon Urias. He moved to third on a sacrifice bunt, and Rutschman cashed him in with a two-out single up the middle that gave the Orioles a 3-0 cushion.

Ryu's batterymate, Danny Jansen, cut that deficit to 3-2 with a two-run blast in the bottom of the second inning.

Ryu served up a single to Santander to begin the third inning but erased him on a double play ball by Austin Hays. Ryu then struck out Henderson looking at a fastball.

Ryu's teammates did their part to get Ryu off the hook, with Brandon Belt tying the game at 3-3 with a solo homer in the bottom third.

Ryu tried to hold up his end of the bargain, too. He pitched around a leadoff single by Westburg in the fourth inning. And with two runners on with one out in the fifth, Ryu cleaned up the mess by getting Hays to bounce into his second double play of the game.

Right-handed reliever Trevor Richards began warming up in the bullpen during the top fifth, but Ryu went back out to open the sixth inning.

The decision to keep Ryu in the game didn't pay off for the Blue Jays, as Ryu served up a leadoff homer to Henderson to put the Orioles back on top at 4-3.

Richards was called in from the bullpen to end Ryu's night after 80 pitches, 54 of them for strikes.

The Orioles led off four of their six innings against Ryu with a hit -- a home run, two singles and two doubles. (Yonhap)