Doosan Bears manager Lee Seung-yuop speaks with reporters at Jamsil Baseball Stadium in Seoul, March 13. Yonhap

Four games into the preseason in the Korea Baseball Organization (KBO), Doosan Bears manager Lee Seung-yuop isn't happy with what he has seen from his young pitchers, the team's 3-1-0 (wins-losses-ties) record notwithstanding.

"They're improving bit by bit, but they have to be better," Lee told reporters at Jamsil Baseball Stadium in Seoul on Thursday, before the Bears hosted the Kia Tigers. "Some of our pitchers aren't up to the level that they were at last year. They have to step up. I am not happy with where they are."

Lee singled out right-handed reliever Choi Jong-in, who had a scoreless month of September last year and had been expected to take up a big spot in the Bears' bullpen this year. The 23-year-old has given up three earned runs in one inning of work on three hits and two walks this spring.

Closer Kim Taek-yeon, the reigning Rookie of the Year, is also not 100 percent, Lee said, adding that the veteran setup man Lee Young-ha is the only reliever he can fully trust at the moment.

"I don't know what these young guys did over the winter," Lee said with a wry smile. "We have six games left in the preseason, and it's about time they started putting up some numbers. At the very least, they should start pitching the way they're capable of pitching."

Lee has fewer concerns about his lineup. Outfielder Kim Min-suk, acquired in a trade with the Lotte Giants, has gone 6-for-16 with two walks at the plate and has played strong defense in left field

"On defense, Min-suk has been better than we expected," the manager said. "We will continue to test him in the leadoff spot. He has not yet been tested against tough left-handed pitchers, but so far, he has been really good for us." (Yonhap)