Urshela had missed the prior four games with back soreness but he fell down awkwardly Thursday at Texas. He was on crutches after the game and X-rays revealed the fracture.
Also, third baseman Anthony Rendon was held out Friday against the Royals because of soreness in his left wrist.
Rendon was hit by a pitch in the first inning Thursday in Texas. Though he stayed in the game, he did not swing.
X-Rays were negative and he's listed as day-to-day.
The Angels won 3-0 on Friday to hand Kansas City its 10th straight loss.
The Associated Press contributed to this report.