Surprise, Ariz. ? Kansas City Royals prospect Henry Barrera walked off the mound holding his right arm and wincing in pain during the team’s final intrasquad game.

The team said the preliminary diagnosis was Barrera has a strained right flexor, and he was scheduled to have an MRI. A club spokesman said it would be 24 to 48 hours before the full extent of the injury would be known.

Barrera, who has a 97 mph fastball, had reconstructive elbow surgery in 2009 and worked just 33 innings last year in the minors. In 16 appearances for Double-A Northwest Arkansas, he struck out 25 in 25 innings while going 3-1 with a save, holding opponents to a .193 batting average.

The Royals showcased five young left-handers late in the game — John Lamb, Will Smith, Danny Duffy, Everett Teaford and Brandon Sisk.

Manager Ned Yost said Lamb and Smith looked good and Duffy “had good stuff.”

The 21-year-old Smith worked a perfect inning, while Lamb, 20, gave up a single.

“The adrenaline was flowing a little more,” Smith said. “It feels more like a game than a bullpen or throwing batting practice.”

Smith threw 10 pitches, including striking out Alex Gordon looking on a full count and retiring Jacob Kuebler, Gordon’s cousin, on a groundball.

“I guess I won’t be getting any Christmas cards from that family,” Smith said with a laugh.

The 22-year-old Duffy allowed a two-out single, but nothing else.

“It felt good. I was a little side-to-side, but it was the first outing.,” Duffy said. “I wasn’t straight on-line. I was cutting myself off a little bit. I felt like I was letting it go. My arm feels really good and strong. That’s night and day from last year.”

Teaford, who led the Royals organization with 14 victories last year, is the only one of the five on the 40-man big-league roster, and none has pitched in the majors. He and Sisk, who was not drafted and began his pro career in an independent league, each gave up a run.

“I’m not putting much weight on an intrasquad inning,” Yost said. “I just wanted them to get through it.”

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Note: Gordon had a feast-or-famine afternoon. He hit a three-run homer and struck out looking three times.