ST. LOUIS -- There were already enough questions surrounding the viability of the San Francisco 49ers’ rebuilt offense this offseason. But throw in injuries and ineffectiveness and you have to wonder whether it simply is time to throw in the towel on this No. 32-ranked offense and start from scratch.

The Niners’ 27-6 loss to the St. Louis Rams on Sunday at the Edward Jones Dome only brought more urgency to this query.

Sure, the Niners were without starting running back Carlos Hyde (foot) and leading receiver Anquan Boldin (hamstring), but then they lost backup running back Reggie Bush (knee) and third-string back Mike Davis (hand), leaving Kendall Gaskins, signed off the practice squad on Saturday with Jarryd Hayne waived, as the only back.

The Niners are not about to bench quarterback Colin Kaepernick in favor of Blaine Gabbert because, well, the staff still believes Kaepernick gives them the best chance to win. That may or may not be accurate, especially with a decimated and -- some would suggest -- deplorable roster lacking quality depth.

And really, coming into the season, that was the biggest question: Was the depth any good?

What were they thinking? Sure, the Niners trust Gaskins more than Hayne, which is why they elevated Gaskins from the practice squad and waived Hayne. But after Bush went down, Gaskins and Davis combined for 2 rushing yards on 11 carries in the first half before Davis' injury.

One reason to get excited: Kaepernick was quick and crisp with his passing on the Niners’ initial possession, completing his first three passes, on their first three plays, for 28 yards.

One reason to panic: With no timetable on Hyde’s return from a stress fracture in his left foot, Bush’s left knee an issue and Hayne waived (though the Niners do hope to re-sign him if he clears waivers), Davis and Gaskins offer little in terms of depth. Davis lost a yard on three consecutive carries to get stopped for a safety.

Fantasy watch: The Niners' offense began and ended with Kaepernick. He completed 20 of 41 passes for 162 yards and led the team with 28 yards rushing.

Ouch: The Niners lost four players for the game in the first half -- RBs Bush (knee) and Davis (hand), TE Garrett Celek (concussion) and special-teams ace L.J. McCray (knee). Cornerback Keith Reaser (ankle) was questionable to return at halftime. And then rookie punter Bradley Pinion suffered a calf injury.

And the game ball goes to? Phil Dawson provided the scoring as the veteran place-kicker showed his wares in the great indoors, ending the Niners’ first drive with a 54-yard field goal. He converted a 26-yarder before halftime. He is 13-of-14 on his field goals thus far and 2-of-2 on kicks of 50 yards or longer. He also supplied a 47-yard punt.

Up next: The Niners (2-7) return to Santa Clara for their final game before the bye week, playing host to the Atlanta Falcons (6-2) next Sunday. The Niners have won the last two meetings, including the 2012 season NFC title game, after dropping the previous four meetings dating back to 2004.