KANSAS CITY -- Royals left-hander Danny Duffy, who's on the 10-day injured list with a strained left hamstring, came out of his two-inning simulated game Friday feeling great, he said on Saturday.

The next step, Duffy said, would be to throw a four-inning, up-and-down sim game on Tuesday in Baltimore.

“We’re just trying to build his pitch count back up, get him to 60,” Royals manager Ned Yost said.

Yost added that the Royals had considered sending Duffy, who suffered the injury on the last road trip in Boston, out on a rehab assignment next week.

“But our Triple-A and Double-A teams [are on the road],” Yost said. “We didn’t want to send him around the country just for that. Everything is right on schedule. It’s been [a little less than two weeks] and his side sessions have been game-like.”

If all goes well, Duffy could possibly be activated next weekend while the Royals are in Cleveland.

Lopez gets another start

While right-hander Brad Keller could have pitched this Monday on normal rest, Yost decided instead to give Keller another day’s rest and go with right-hander Jorge Lopez instead.

“[Keller] is getting up near his high-water mark for innings in a season,” Yost said. “An extra day’s rest will be good for him.”

Actually, with 158 innings pitched, Keller already is at his high-water mark. He threw 142 innings in the Minors in 2015, and 140 1/3 frames last season.

Lopez, meanwhile, remains puzzling. Though he has some of the best stuff on the Royals' pitching staff, and he tantalized the organization with a near-perfect game last September, he's posted a 6.51 ERA this season. In his last start, Lopez failed to make it out of the second inning.

“A little bit [puzzling],” Yost said. “But he’s got great stuff. It’s just a matter of putting it all together in the strike zone. We’ve seen glimpses of him [being really good]. It’s there. It just needs to come to fruition.”