The San Francisco 49ers have enjoyed a lot of great moments over the past year. Today was not one of them. The Miami Dolphins eviscerated the 49ers on Sunday, 43-17, in Santa Clara.

Perhaps the day’s low point proved to be the benching of 49ers quarterback Jimmy Garoppolo, who finished the day 7 of 17 for 77 yards and two interceptions in his first game since getting injured during the Week 2 game against the Jets. The seven-year veteran was replaced by backup quarterback C.J. Beathard after halftime.

Garoppolo finished with a 15.7 passer rating – the worst of his career as a starting quarterback in the NFL. During postgame press conferences, both Garoppolo and 49ers head coach Kyle Shanahan seemed to think the former’s high ankle sprain was a major cause for his shaky play on Sunday.

“Watching how we were playing as a whole (and) watching how he was playing, you can tell he was affected by his ankle,” Kyle Shanahan said postgame. “I know he doesn’t normally throw the ball that way and I think he was struggling a little bit because of it. The way the game was going, I wasn’t going to keep putting him in those positions knowing we were going to have to throw it a lot to come back.

“I think it hurt him from being at his best.”

Kyle Shanahan on 49ers.com

No long-term prognosis was given on Garoppolo as the 49ers are set to begin perhaps the most challenging stretch of its season. Here are San Francisco’s next five games:

• 10/18 – vs. Rams
• 10/25 – at Patriots
• 11/1 – at Seahawks
• 11/5 – vs. Packers (Thursday)
• 11/15 – at Saints

If the 49ers don’t get their act together, the season may spiral out of control quickly.

The day was even worse for the 49ers defense. They gave up 30 first-half points and allowed Dolphins quarterback Ryan Fitzpatrick to throw for 350 yards and three touchdowns.

The 43 points scored by Miami is their highest point total since 2015. Meanwhile, the last time the 49ers gave up at least 40 points was last December in a 48-46 win over the Saints.