The Spurs are not, technically speaking, out of the playoff race. One could easily imagine scenarios where the Silver and Black are able to climb back out of the 5 game hole they’ve dug for themselves with only 28 games to go.
Perhaps Ja Morant accidentally dunks the ball so hard that he creates a momentary tear in the fabric of space-time, which then sucks the entire Grizzlies franchise into an alternate universe. The league doesn’t currently have any rules concerning how the tiebreaker would work in such a scenario, so it seems reasonable to suggest the last playoff spot would go to a team that still exists, and maybe the Spurs could be that team (assuming they can catch the Trail Blazers, obviously).