The Chargers hired Norv Turner yesterday, although Ryan reportedly was a serious candidate for the job.
"Sure I'm disappointed," Ryan told The Sun less than an hour after news broke about Turner. "But I would be disappointed if the Ravens made a Super Bowl run and I wasn't a part of it. We have some unfinished business here."
Ryan will return to a defense that will bring back at least 10 starters after finishing last season ranked No. 1 in the NFL.
Based on the creative schemes Ryan used last season and his reputation as being a players' coach, the Chargers met with Ryan on Thursday about their vacancy. It was the first head coaching interview for Ryan, who didn't receive a call from the other six teams that sought a new coach this offseason.
Over the weekend, it was reported by ESPN and San Diego radio stations that the Chargers were deciding between Ryan and Turner.
The Chargers ultimately chose Turner, the San Francisco 49ers offensive coordinator, who has been unsuccessful in two stints as an NFL head coach. He's 58-82-1 with one playoff appearance in nine seasons leading the Washington Redskins (1994-2000) and Oakland Raiders (2004-2005).
"Things like that happen," Ryan said. "I was a little shocked, but I was happy to at least interview with those guys. I really thought I had a great chance at it. But life goes on and I'm excited about the opportunities we have in Baltimore for next season."
The Chargers, who fired Marty Schottenheimer on Feb. 12, had interviewed Ryan, Turner, 49ers assistant head coach Mike Singletary, Chicago Bears defensive coordinator Ron Rivera, Atlanta Falcons defensive coordinator Mike Zimmer and New Orleans Saints defensive coordinator Gary Gibbs.
Ryan, 44, said he gained valuable experience from the process.
"I know more now than ever that I am ready for that responsibility," Ryan said. "I think they realized that when I got in there. At first, maybe they had different expectations. But when I went in there, I was prepared for it. All I had to be was myself. It'll be good enough one day."
If the Ravens have continued success, Ryan should have other shots at becoming a head coach.
The Ravens' two previous defensive coordinators - Marvin Lewis and Mike Nolan - have gone on to become NFL head coaches.
"Nothing is guaranteed," Ryan said. "All I can do is the best job I can and see where it goes."
In two seasons with Ryan as coordinator, the Ravens' defense finished fifth and first. The Ravens could bring back their starting defense intact if they choose to use the franchise tag on outside linebacker Adalius Thomas by Thursday's deadline.
In 2007, half of the Ravens' games will be played against offenses ranked in the top 11 last season.
"Last year's schedule was challenging with the offensive teams we faced, but this one is going to be more so," Ryan said. "But, hey, bring it on. We're ready to put our best foot forward."
The NFL's coaching changes since the end of the season:
Arizona Dennis Green (fired)
Atlanta Jim Mora (fired)
Dallas Bill Parcells (retired)
Miami Nick Saban (resigned)
Oakland Art Shell (fired)
Pittsburgh Bill Cowher (resigned)
San Diego M. Schottenheimer (fired)
*-First-time NFL head coach