Phoenix ? Ben Sheets took a big step forward in his slow recovery from offseason back surgery.

Sheets made his spring debut and pitched a scoreless inning in the Milwaukee Brewers’ 6-4 loss to the Kansas City Royals on Thursday. Scheduled to throw one inning or 25 pitches, Sheets needed just 12 pitches to retire the side in the first.

After striking out leadoff man Aaron Guiel, he hit Angel Berroa with the first pitch, struck out Terrence Long and then retired first baseman Ken Harvey on a first-pitch groundout.

“My back felt good,” Sheets said. “I wasn’t even thinking about it. I located the ball well. That was good to see.”

Sheets, a 26-year-old right-hander, established himself as one of the premier pitchers in the National League last season. He set personal bests for victories (12), earned-run average (2.74), innings (237) and strikeouts (264, a franchise record).

Right-hander Wes Obermueller, who is vying for a spot on Milwaukee’s pitching staff, surrendered a base hit to Mark Teahen, who scored on a double by Ruben Gotay. The Brewers scored four runs in the second inning against veteran right-hander Kevin Appier.