When asked about playing for new coach Jim Tomsula and the 49ers organization, Dockett told Fox Sports Radio in Arizona of himself, "This guy is awesome, man ... They hit the lottery, they got themselves a dog a-- player."
Dockett's agent, Drew Rosenhaus, announced Dockett's signing Thursday on Twitter. The team later confirmed it.
Congrats to the newest Niner! pic.twitter.com/8lGnY2fwEG— Drew Rosenhaus (@RosenhausSports) March 5, 2015
Dockett signed a two-year, $7.5 million contract with the 49ers, with $4 million being paid in the first season and $2 million guaranteed, a league source told ESPN NFL Insider Adam Schefter.
Dockett's 11-year run with the Arizona Cardinals ended Friday when the team released him. The Cardinals were open to re-signing him at a lower rate than the $6.8 million he was scheduled to earn in 2015. Docket said he gave Arizona plenty of chances to work out a deal.
"I was willing to restructure my contract," he told Fox Sports Radio. "I was willing to take less money than what [San Francisco] was offering.
"Organizations pay who they want to pay ... I gave the Arizona Cardinals two, three times to match the offer, and when I gave them two, three times to match the offer, I was willing to take less than what San Fran offered."
Dockett said less than $500,000 was the difference between him staying in Arizona and deciding to sign with San Francisco.
The 33-year-old missed all of the 2014 season after tearing his ACL during training camp in August. Before last season, Dockett had missed two games in 10 seasons.
He strengthens the 49ers' defensive line while weakening a division rival in the Cardinals. His signing also might signal that the 49ers won't wait for Justin Smith to decide whether to retire or return for a 15th season.
Dockett finished his career with the Cardinals with 459 tackles, 40.5 sacks, 12 fumble recoveries, seven forced fumbles and four interceptions.
His three sacks in Super Bowl XLIII tied Reggie White for most in a Super Bowl.
Dockett also tweeted about the move Thursday.
I love you all. The ones that doubt , The ones that Love, The ones that hate, The ones who believe and don't believe. #inDOCKETTitrust😘— DARNELL DOCKETT (@ddockett) March 5, 2015
The Cardinals tweeted a thank-you to Dockett for his 11 seasons with the team on Thursday.
Although insisting he wasn't bitter, Dockett did note he'll have plenty of opportunities against his former team and new NFC West foe.
"The biggest thing," he said, "I get to play Arizona two times a year, so you know what time it is."
ESPN.com 49ers reporter Paul Gutierrez contributed to this report.