Sierra agreed Monday with Atlanta on a minor-league contract and received an invitation to MLB spring training, Double-A Mississippi broadcaster Chris Harris reports.

The Angels outrighted Sierra to Triple-A Salt Lake on Sunday.

The Angels designated Sierra for assignment following Tuesday's 4-3 win over the Athletics, Rhett Bollinger of MLB.com reports.

Sierra is out of the lineup for Sunday's game in Detroit.

Sierra isn't starting Friday against the Twins, Jeff Fletcher of The Orange County Register reports.

Sierra went 2-for-5 with a double, two RBI and two stolen bases Wednesday against the Athletics.

Sierra is out of the lineup for Tuesday's game against the Athletics, Jeff Fletcher of The Orange County Register reports.

Sierra will start in center field in Sunday's game in Seattle.