I believe it's more than likely a Spring Training photo (note the palm trees in the background). The M's never wore blue pants after 1984. But the yellow 3 Dimensional "S" on the cap indicates a timeframe of 1987 - 1992. Since Griffey broke into the majors in 1989, that limits the timeframe to 1989-92.
Perhaps someone can shed some additional light. Along these lines, please be sure to check out the latest TSOG segment, which features Mariner's defunct Caps... it covers every style leading up to the present.
Link below...
https://www.youtube.com/watch?v=LuEl2pXYfmQ&t=606s