Martinez was optioned to Triple-A Salt Lake on Thursday, Jeff Fletcher of The Orange County Register reports.
Martinez will head to Salt Lake after spending nearly a week with the major-league roster, going 1-for-3 with a strikeout in his brief stint with the Angels. The team is expected to activate Logan O'Hoppe (wrist) from the 10-day injured list Friday, and he'll replace Martinez with the big-league club.