"I got the call at 11:45 (p.m.). ... I was just picking up dinner at Taco Bell," said Robertson, 29, who made his Major League debut for the Rangers in 2014.
He hit .271 in 70 games for the Rangers, then was acquired by the Angels in November for cash considerations.
Manager Mike Scioscia said the Angels needed some protection in the outfield. He said calling up Robertson, primarily a center fielder, had been in the plans for some time, but the ball center fielder Mike Trout fouled off a toe Saturday night hastened the move by a day -- although Trout was able to play Sunday.
"We felt like he was the best fit right now," Scioscia said. Right fielder Kole Calhoun was the emergency center fielder before Robertson arrived.
Robertson was batting .245 with one home run and 13 RBIs in 51 games for Salt Lake, where he played left and right field, in addition to center.
"I was swinging the bat well, just a little bit of being unlucky," Robertson said of his average. "It's been that way since the beginning of the year. But I was doing the things I needed to do, competing every day."
The callup couldn't have been more timely. Robertson said he missed a six-hour bus trip to Las Vegas that the Bees were taking after Sunday's home game.
Cron (.204, one homer, six RBIs in 35 games) had just been recalled June 6 from a 10-game stay at Salt Lake, but had just 10 at-bats since that return. With two games in a National League park (Arizona) upcoming, Scioscia said, "We didn't see many at-bats for him" in the next week.
• Left fielder/DH Matt Joyce (.178, four home runs, 17 RBIs in 55 games) was not in the lineup Sunday against right-hander Sonny Gray.
"Matty needs to exhale, for sure," Scioscia said of the break. "It's up to Matt to find his way through this. We've tried to grind it out, and it's not working."
The Angels have been hoping for three months that Joyce would the player he was with the Rays, and fill a spot in the middle of their lineup. He batted ninth Saturday night.
• The Angels signed their sixth-round pick, Loyola Marymount shortstop David Fletcher. ... They also signed former Major League left-hander Jo-Jo Reyes, 30, to a Minor League deal. He was pitching for Campeche in the Mexican League, and was selected to the league's All-Star team. Reyes, a 2003 second-round pick of the Braves, last pitched in the Major Leagues in 2011. He was 12-26 with a 6.05 ERA in 70 games (65 starts) for the Braves, Blue Jays and Orioles.
• Angels right-hander Trevor Gott, 22, made his Major League debut with a perfect ninth inning on seven pitches (six strikes).