Stephen A. Smith applauds San Francisco GM John Lynch for the job he's done bringing in a franchise quarterback in Jimmy Garoppolo and CB Richard Sherman, who has spent his entire career in the NFC West. (1:31)

New San Francisco 49ers cornerback Richard Sherman says playing in the NFC West and having the opportunity to face his former team, the Seattle Seahawks, twice per season played a role in his free-agency decision, telling The MMQB on Sunday that "I'm vengeful in that way."

Sherman acknowledged his feelings after seeing the reaction from Seahawks fans to his signing with one of their rivals.

"I love the fan base to death, and I loved playing there. It was such a great opportunity. I helped the organization get to a great place and stay there," Sherman told The MMQB. "But now it's like I abandoned them. People are out there burning my jersey. Come on. I'm not the one who let me go. They let me go. I didn't abandon anybody."

The 49ers and Sherman agreed to a three-year contract that was officially announced by the team Sunday. Terms of the contract were not disclosed, but Sherman told ESPN's Josina Anderson on Saturday that the incentive-laden deal is worth up to $39.15 million.

Sherman told The MMQB that the contract contains guarantees that roll over to the following year if he makes the Pro Bowl.

Richard Sherman will be on the other sideline of the 49ers-Seahawks rivalry in 2018. Nick Wosika/Icon Sportswire

"I don't think any agent in the business could have done a better job of negotiating this contract," Sherman said. "As long as I'm content with what I'm making, nothing else matters to me.

"Once I make a Pro Bowl, $8 million the next year is guaranteed for me. It gives me the ability to control my destiny. The 49ers have skin in the game. I have skin in the game. In my former contract, no matter what I did this year, nothing would be guaranteed to me next year. I couldn't feel secure in my contract. Now, if I play the way I know I'm capable of playing, I know I'm going to get paid."

Sherman said he called the Seahawks to gauge their interest on matching the 49ers' offer but was turned down based on the incentives. He also reached out to the Oakland Raiders and Detroit Lions before finalizing the deal in San Francisco.

The MMQB also detailed some of the negotiations between Sherman and the 49ers, including general manager John Lynch and executive vice president of football operations Paraag Marathe. Sherman was acting as his own agent, and Marathe said he was impressed by the cornerback's preparation.

"Richard came into the meeting with us having read all the contracts for all the top cornerbacks past and present," Marathe said, adding that Sherman "studied our contracts and knew who we'd given real guaranteed money to."

Agreeing on a deal brought to an end a whirlwind couple of days for Sherman.

"It was chaos," Sherman said in a conference call Monday.

According to Sherman, almost immediately after the Seahawks released him on Friday, the 49ers got in touch with him and invited him to visit with the team. Sherman and his fiancée, Ashley, flew to San Jose and had dinner with Niners coach Kyle Shanahan and his wife, Mandy, at a restaurant in nearby Los Gatos. Defensive coordinator Robert Saleh, who already knew Sherman from his time as a defensive assistant in Seattle, joined them.

On Saturday, Sherman met with more of the 49ers brass, including Lynch and Marathe. Included in the visit was a series of medical tests intended to give the Niners a better idea of how far along Sherman was in his recovery from not only the right Achilles injury but also from a more recent and minor surgery to clean up bone spurs in his left ankle/heel.

Ultimately, it became clear to Sherman that his best fit would be with his once-hated rival in San Francisco, a fit Sherman attributed to many things, including a desire to stay on the West Coast, the presence of quarterback Jimmy Garoppolo, Shanahan's offensive scheme and, of course, the chance to play the Seahawks twice a year.

"Neither side really wanted to walk away without a deal because we felt like there was a great relationship and great understanding and something that both sides would benefit from," he said on the conference call. "And we came to an agreement. It was awesome."

Upon landing Sherman, the Niners filled their biggest offseason need for help at cornerback. They almost certainly aren't done adding to the position that last year contributed to allowing a Total QBR of 87 last season, second-worst in the league, according to ESPN Stats & Information. At the NFL scouting combine, Lynch said it didn't take a "savant" to see the team's need at the position.

Once healthy, Sherman will be expected to start opposite Ahkello Witherspoon in the Niners' Cover 3 defense. That scheme is similar to the one Seattle has run for many years and though the Seahawks have become a bit more diverse defensively in recent years, it's still the foundation of what they've done.

Sherman doesn't believe there will be much adjustment in joining the Niners or moving to the Bay Area considering his previous time in college at nearby Stanford. The biggest change? Wearing a different team's colors for the first time in his NFL career.

"I've spent a lot of time wearing a red jersey in the Bay, so I'm sure I'll be able to figure it out," Sherman said.

ESPN's Nick Wagoner and The Associated Press contributed to this report.