Raleigh will be part of the Mariners' 60-man training roster.
The 23-year-old switch hitter is Seattle's best catching prospect, but that is damning with faint praise. He had a 134 wRC+ with a .274 ISO at High-A last year but hit just .228 with a 29.6 percent strikeout rate in 39 games after a promotion to Double-A. Raleigh may get some time in the majors this year, but he is firmly behind Tom Murphy and Austin Nola on the depth chart.