The San Francisco 49ers opened their organized team activities this week minus two dissatisfied starters.

Star tight end Vernon Davis and starting right guard Alex Boone are not participating in this week's voluntary activities because they are unhappy with their contracts, according to multiple reports. Both players are signed through 2015 and hoping to garner an extension.

Davis signed a five-year, $37 million contract in 2010 that made him the highest-paid tight end in the NFL at the time. Since then, the New England Patriots' Rob Gronkowski and the Dallas Cowboys' Jason Witten each received more lucrative deals on average, while Jimmy Graham likely would get a bigger deal should he sign with the New Orleans Saints long term.

Graham was franchised this spring at $7,503,000 but is filing a grievance to be considered a wide receiver, which would net him $12,132,000 million in 2014.

Davis registered 13 of the 49ers' 21 touchdown receptions last year, becoming the second tight end in league history to notch at least 13 receiving scores in multiple seasons. The 30-year-old is likely looking for more long-term security with two years remaining on his contract.

Boone's reported unhappiness stems from the deal the lineman signed in 2011 before becoming a starter. It paid him an average of $1,635,000 per season with a $2.59 million salary-cap hit in 2014. However, he started every game over the past two seasons, outperforming his deal.

However, it appears Boone would have significantly less leverage than Davis after San Francisco used two third-round picks addressing the interior of the offensive line. San Francisco took USC's Marcus Martin and Clemson's Brandon Thomas, although Thomas is likely to miss the season after sustaining an ACL tear during a pre-draft workout.

The 49ers also have Daniel Kilgore, who is also versed in all three interior positions and signed a three-year extension this offseason.

--- The San Diego Chargers have all of their six 2014 draft picks under contract after cornerback Jason Verrett signed a four-year deal on Thursday.

The contract includes a fifth-year option after the 2016 season.

The Chargers' first-round pick (No. 25 overall) had nine interceptions and 160 tackles in three seasons at Texas Christian. The 5-foot-10, 189-pound Verrett was a second-team All-American selection in 2013.

--- The Seattle Seahawks agreed to a new contract with wide receiver Doug Baldwin, according to reports Thursday.

NFL Network reported the deal is for three years and $13 million -- an average of $5.45 per year in new money, and can be worth up to $6.5 million per year with incentives. Baldwin was scheduled to make $2.2 million this season as a restricted free agent. The new deal allows Baldwin to hit unrestricted free agency after the 2016 season. according to ESPN.com.

The undrafted Baldwin, 25, came into the league in 2011 and led the team's receivers in catches (51), yards (788) and touchdowns (four). Last season, he ranked second in receptions (50) and yards (778) and tied for first with five touchdowns.

--- Seven weeks removed from ankle surgery, New York Giants quarterback Eli Manning practiced for the second day in a row.

Manning is taking snaps from center, dropping back, rolling out and throwing passes to his receivers, backs and tight ends. Hesaid it helps to be on the field with the Giants learning new offensive coordinator Ben McAdoo's offense.

"The last few weeks, I've been doing most things from a practice standpoint," Manning said. "We're still being smart about things and not trying to overdo it, but definitely, football activities, I feel like I can do them all full."

--- New Orleans Saints safety Jairus Byrd underwent back surgery that the team hopes will have him back at full speed in time for training camp, coach Sean Payton said Thursday.

Payton said the surgery for the Saints' prized free agency acquisition didn't have to be done but that all parties decided it would be best for Byrd long-term after a disc issue had been nagging him for the past month.Payton said Byrd will probably miss all of the organized team activities and minicamp over the next month.

The three-time Pro Bowler signed a six-year, $54 million contract that included $20.3 million in guaranteed money, plus another $6 million guaranteed for injury only. Byrd had 22 interceptions and 11 forced fumbles in five seasons with the Buffalo Bills.

--- The Carolina Panthers signed their second-round draft choice, defensive end Kony Ealy from Missouri, the team announced Thursday.

The 6-foot-5, 275-pound Ealy, the 60th overall pick, played in 38 games with 25 starts at Missouri, entering the NFL following his junior season. He produced 93 tackles, 27.5 tackles for loss, 14 sacks, 19 quarterback pressures, four forced fumbles, one fumble recovery, one interception and 13 passes defensed.

---The Buffalo Bills signed offensive lineman Cyrus Kouandjio to a rookie contract on Thursday.

Terms of the deal were not announced for the team's second-round pick (No. 44 overall) in the 2014 NFL Draft. Kouandjio, a native of Cameroom, was the last of the Bills' seven draft picks this year to sign. The 6-foot-7, 322-pound Kouandjio started the final 27 of the 35 games he played at left tackle Alabama. He was a first-team All-Southeastern Conference pick last season.

--- The Chicago Bears on Thursday signed tackle/guard Michael Ola, who was released by the Miami Dolphins.