Shelley received a three-year deal for $1.1 million per season.
The acquisition of the 6-2, 223-pound Meszaros and the signing of Coburn and O'Donnell give the Flyers one of the league's deepest, biggest, and best defenses.
Also one of the most expensive.
The Flyers' top five defensemen - Pronger, Matt Carle, Kimmo Timonen, Coburn, and Meszaros - have a combined $21.8 million cap hit (of the $59.4 million maximum) for 2010-11. That computes to $4.4 million per player.
O'Donnell, a steady defenseman who was fourth on the Kings with a plus-14 rating in 78 games last season, said he signed with the Flyers because of his friendship with Pronger and because he thought the team was close to winning a Stanley Cup.
"If I didn't think Philly was in that group of teams that was right there on the cusp, I wouldn't have signed with Philly," O'Donnell said.
General manager Paul Holmgren called Meszaros "a young, durable defenseman who can play in all situations."
Meszaros, 24, had six goals and 11 assists and was minus-14 for lowly Tampa Bay last season. The Flyers are hoping he returns to the form he showed early in his career, when he played in Ottawa.
A member of Team Slovakia in the 2010 Winter Olympics, Meszaros was slowed by shoulder surgery and a broken jaw in Tampa. Playing for Ottawa, he was named to the NHL's all-rookie team in 2006. That season stands as the best of his five-year career: 10 goals, 29 assists, and a plus-34 rating.
"I'm excited," said Meszaros, who played for Flyers assistant GM John Paddock when he coached in Ottawa. "Philadelphia is always a tough team to play against, and now I'm joining them, so it's great."
The Flyers were unsuccessful in trying to land defensemen such as Dan Hamhuis (signed with Vancouver), Paul Martin (signed with Pittsburgh), or Anton Volchenkov (signed with New Jersey). They had also said they were interested in signing another goalie but couldn't land Dan Ellis (signed with Tampa Bay) or Chris Mason (signed with Atlanta). Evgeni Nabokov and Marty Turco were still unsigned heading into Thursday night.
Pittsburgh lost free-agent defenseman Sergei Gonchar to Ottawa, but the Pens picked up two big defensive pieces by signing Martin (five years, $25 million) and Zbynek Michalek (five years, $20 million), two highly sought-after defensemen.
New Jersey, in effect, replaced Martin by signing rugged defenseman Volchenkov, whom the Flyers had coveted. The Devils also signed talented defenseman Henrik Tallinder, formerly of Buffalo.
Meszaros, selected in the first round by Ottawa (23d overall) in 2004, is a lefthanded shooter who prefers to play the right side. He will turn 25 on Oct. 13.
Meszaros has a four-year deal with an annual cap hit of $4 million. By comparison, Volchenkov, regarded as one of the elite free-agent defensemen, signed a six-year deal for $4.25 million per season with rival New Jersey.
"Six years is a long time for a midlevel type of guy," said one Flyers official.
O'Donnell had 15 points with Los Angeles last season. During his 15-year career, O'Donnell - the Minnesota Wild's first captain, in the 2000-01 season - has appeared in the Stanley Cup Finals with New Jersey in 2001 and Anaheim in 2007.
The hard-nosed Shelley, 34, had a combined two goals in 57 games with San Jose and the Rangers last season, and he apparently will replace feisty winger Arron Asham (10 goals), who was impressive in the playoffs.
The Flyers recently gave offer sheets to restricted free agents Dan Carcillo and Darroll Powe, but they will have to make some other moves to get them both under the cap.
The Flyers have about $578,000 in cap space. That will grow with the expected demotion/release of Riley Cote ($550,000), which would give them about $1.1 million in cap room.
Contact staff writer Sam Carchidi at 215-854-5181 or email@example.com. Follow on Twitter at www.twitter.com/BroadStBull.