None of that guarantees anything by Sunday. This is a four-game set, and the two clubs play three more times before this particular game happens, so whatever shape either roster is in by Sunday's first pitch at 1:10 PM PT could look different than it does right now.
Oakland's last-5 stretch includes a lopsided 9-2 win over Texas, so it's not as if the lineup has been lifeless, injuries aside. Seattle's last two wins came against a Boston team that had it 8-3 and 9-6, meaning the offense has shown some life against quality pitching, not just against bad teams padding the schedule.
The injury sheet is where this game actually gets interesting. Oakland is without three middle-of-the-order regulars for the season, plus a shortstop who's about to have shoulder surgery, which leaves manager Mark Kotsay piecing together a lineup on most nights. Seattle isn't fully healthy either, with a couple of bullpen arms out and Brendan Donovan still working back from a concussion, but the gap in overall health between these two rosters is not close.
Sunday's game is the last of four between these two clubs this week, and by the time it's played, both teams will have had three more games to shuffle bullpens, rest regulars, or simply confirm what everyone already suspects about the standings. Either way, Seattle gets to try to build on its own momentum against a club that's given up very little resistance lately.