The move costs the Cowboys $10.6 million, but it is possible the sides could work out a long-term deal, according to Spencer's agent, Jordan Woy.
"We will be working on a long-term deal," Woy said. "Anthony played very well last season and he would like to know he has a home here for several years."
However, it is also possible the Cowboys could look to trade Spencer for draft picks.
Spencer had a career-high 11 sacks in 2012 and was named to the Pro Bowl as an injury replacement. Spencer led the Cowboys with 95 tackles, and his eight tackles for loss and 26 quarterback pressures were second on the team.
He reached double digits in sacks last season for the first time in his career while only playing in 14 games. He even took over the play calling later in the season due to injuries to Sean Lee and Bruce Carter.
Spencer will move to defensive end with the Cowboys switching to the 4-3 scheme this year, if he remains on the roster. Owner and general manager Jerry Jones hinted at the NFL scouting combine that Spencer does not have the preferred size for Monte Kiffin's scheme.
Spencer played defensive end at Purdue.
Jones also said Spencer's price on a long-term deal would be too expensive for the team's liking, but added there would be a reasonable way to keep him. While the franchise tag is costly, it is not unreasonable.
The Cowboys will have to restructure more contracts to get under the $123 million cap by March 12 and have worked out agreements to do so with defensive tackle Jay Ratliff and guards Nate Livings and Mackenzy Bernadeau. Cornerback Orlando Scandrick and quarterback Kyle Orton could also have their deals re-worked.
The Cowboys would like to sign Tony Romo to a new deal, which would knock down his $16.8 million cap figure, but have not had substantive talks as of yet.