"Depending upon how large a contract the second player wanted, you may need to do things in the first contract to make sure you had adequate cap room in that particular year to do it," Banner said.
Jackson held out for the first couple of weeks of training camp this summer but ultimately reported. He's scheduled to receive approximately $600,000 in base salary this season, the final year of the four-year rookie deal signed after the Eagles selected him in the second round of the 2008 NFL Draft.
Jackson and his agent, Drew Rosenhaus, believe he deserves to be among the NFL's highest-paid receivers. Jackson had 47 catches for 1,056 yards and six touchdowns last season, and his 22.5 yard-per-catch average led the league.
Banner acknowledged the effects of Arizona Cardinals wide receiver Larry Fitzgerald's recent eight-year, $120 million deal. "Every contract that gets done has an impact," Banner said.
"The closer you get to the season, the less likelihood of something happening," Banner said.
Despite the Eagles' free-agent spending spree, Banner said there was one player -- who he wouldn't name -- that the team wanted to sign but didn't. As it was, the Eagles signed Asomugha, wide receiver Steve Smith, running back Ronnie Brown, quarterback Vince Young, defensive end Jason Babin and defensive tackle Cullen Jenkins.