Martinez was optioned to Triple-A Salt Lake on May 14 and has now been designated for assignment. The 24-year-old slashed just .189/.308/.369 with six home runs and 14 RBI in Triple-A this season. His spot on the 40-man roster will be taken by Gustavo Campero (hand), who was elevated from Double-A Rocket City on Saturday and placed on the 10-day injured list.

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.