LOS ANGELES >> After seven seasons of success and setbacks as a starting NFL quarterback, Jimmy Garoppolo decided it was time to take a step back to recharge his career.

He couldn’t think of a better place to do it than with Sean McVay and the Los Angeles Rams.

“I’m excited to start this new journey,” Garoppolo said today after the Rams officially announced their signing of the longtime San Francisco starter. “I don’t know exactly what’s in store for me — but maybe reset, reinvent, whatever you want to call it. I’m just excited to get back on the football field and start slinging it around with some new guys.”

The 32-year-old Garoppolo also gave some insight into the reason he must sit out the first two games of the new season under suspension for violating the league’s policy on performance-enhancing drugs. The quarterback said the suspension was the result of a mistake in his filing for a therapeutic use exemption for an unspecified substance.

“I just messed up the TUE, really,” Garoppolo said. “I hate to joke about it, but I messed up the TUE when I first got to Las Vegas. Bad timing, I guess.”

Garoppolo agreed to join the Rams last week, two days after Las Vegas released him. His only year with the Raiders was tumultuous and ultimately disappointing, considering Garoppolo started it with a three-year, $72.75 million contract and ended it on the bench behind a rookie.

It was a large step down from his years of success with the 49ers. When he hit free agency, Garoppolo decided he wanted to follow in the footsteps of Tampa Bay’s Baker Mayfield, who revitalized his career in late 2022 with a successful five-game stint under McVay.

“What Baker did, that was tremendous, incredible,” Garoppolo said. “Sean is a phenomenal offensive mind. A lot of the guys around here are. I think that played a big part. Reinventing, whatever you want to call it, a quarterback, having good people around you. It’s not all going to be done by you. You’ve got to have people around you to put you in a good position, call the right plays, all those little things. It’s an opportunity, and I got excited. It just seemed right.”

After beginning his career behind Tom Brady in New England, Garoppolo has been a starting quarterback for most of the past seven seasons, not including several lengthy injury absences.

In LA, he will be the backup to Matthew Stafford, who will enter his 16th NFL season and his fourth as Los Angeles’ starter. The 36-year-old Stafford showed no signs of slowing down during a strong 2023-24 season, leading the Rams to 10 wins and a playoff berth while earning a Pro Bowl selection.

Garoppolo said Stafford is a “normal, down-to-earth guy. Super Bowl champion, I think that speaks for itself, and his arm talent I don’t think gets enough credit, but I think people are starting to notice. I’m excited to work with him, learn from him.”

The signing of Garoppolo and his 63 career NFL starts signals a shift in attitude by the Rams about their backup quarterback job, which often has been filled with untested players during McVay’s first seven seasons.

That money-saving attitude came back to bite the Rams in each of the past two seasons when Stafford went down with injuries, leading to ineffective play from the seldom-used reserves. Los Angeles eventually had to sign Mayfield in 2022 and Carson Wentz last season when McVay’s initial backup plan proved unsuccessful.

Although it clearly wasn’t the motivating factor, the Rams are undoubtedly aware of Garoppolo’s 8-0 record as a starter against Los Angeles in the regular season — part of Kyle Shanahan’s steady dominance over McVay, his close friend and former colleague in Washington. But Garoppolo’s Niners also lost a close NFC championship game to the Rams in January 2022, and McVay’s team went on to win the title.

Shanahan and McVay employ broadly similar offenses, so Garoppolo is already ahead on learning terminology. He also knows several assistant coaches, including offensive coordinator Mike LaFleur, who was his passing game coordinator for four seasons with the 49ers.

While he will miss the first two games, Garoppolo is looking forward to the offseason and the preseason as a chance to start his next chapter before the suspension kicks in.

“Just take it in stride, I guess,” Garoppolo said. “It’s a weird one, but it is what it is, I guess. Attack OTAs, attack training camp and let those first two games pass by. Hopefully we’ll get some dubs, start off 2-0 and keep things moving. … You’ve just got to keep moving on and stay positive.”