MIAMI GARDENS, Fla. >> Five years after losing Super Bowl LIV here, the 49ers’ return to Hard Rock Stadium cruelly coincided with their elimination from this season’s playoff contention — even before kicking off Sunday’s 29-17 defeat to the Dolphins.

Earlier wins by the NFC West-leading Los Angeles Rams and the wild-card seeking Washington Commanders officially extinguished the 49ers’ miniscule playoff chances, projected at less than 1%.

Thus, the outgoing NFC champions are playing out the string. Their home finale is on Monday night, Dec. 30 against NFC-leading Detroit, then the 49ers’ season closes Jan. 5 at the Arizona Cardinals, who led the NFC West in Week 11 but also got eliminated from contention Sunday.

Many hallmarks of this 6-9 season resurfaced Sunday: injuries, penalties, a lack of takeaways, special-teams woes, and a fourth-quarter interception of Purdy, who was hit in the process. That all and them some spoiled the 49ers’ first meeting against the Dolphins here since 2016.

Last time on this field, the 49ers fell 31-20 in Super Bowl LIV once the Kansas City Chiefs rallied in the fourth quarter, when Jimmy Garoppolo infamously overthrew an open Emmanuel Sanders. This time, the 49ers’ last-ditch comeback ended when Purdy got intercepted with under two minutes remaining. The 49ers had pulled within 19-17 on Brock Purdy’s 2-yard touchdown pass to Eric Saubert with 12 minutes to go.

It wouldn’t be a 49ers’ defeat without more health issues, from a first-series exit by linebacker Dre Greenlaw (right calf; not left Achilles), to second-half leg injuries for left tackle Jaylon Moore (quadriceps) and left guard Aaron Banks (knee).

The 49ers offense struggled to run — Patrick Taylor Jr. was their fourth running back — so Purdy turned to George Kittle and Deebo Samuel.