A bye does not only a body good, but the psyche as well. And when the schedule starts to soften up a bit, well, you get the picture.

The San Francisco 49ers were beat up a couple of weeks ago, physically and mentally, after their 42-17 loss at the Denver Broncos. But now they only have four players on the injury report, and no one missed practice either Wednesday or Thursday. Oh, and the opponent they faced before the Broncos, the St. Louis Rams, are in even worse shape now than the 49ers were two weeks earlier.

Colin Kaepernick riddled the Rams’ league-worst pass defense that day with 343 yards passing and three touchdowns without an interception or a sack. Expect more of the same Sunday at Levi’s Stadium, as St. Louis is last in the NFL in completion percentage defense (70.4 %), sacks (6) and Total QBR (86.4).

“It’s a salty opponent,” said Niners coach Jim Harbaugh. “We understand that.”

Come Sunday, though, the Rams, who are just 2-10-1 against the Niners since 2008, might be more seasoning for a 49ers team primed to surge.

“You’ve just got to be on high alert at all times [against the Rams],” Harbaugh added. “There’ll be an onside kick that comes when they’re up 14-0. There’s fakes in the punt return game. There’s fakes in the punt game, in the kickoff return.

“Makes us play at a higher awareness, high alert.”

They're the perfect opponent at the perfect time, then.

Prediction: 49ers 38, Rams 13