Pittsburgh Steelers general manager Kevin Colbert sounds determined to keep big-play wide receiver Mike Wallace, one of the top restricted free agents in the NFL.

"We want Mike to finish his career with the Steelers," Colbert told reporters Thursday at the NFL combine in Indianapolis. "We think he's only scratched the surface of what he can do."

But Colbert wouldn't reveal how the salary cap-strapped Steelers plan on keeping him. If the Steelers place a first-round tender on the 25-year-old Wallace, another team can pry him away by extending an offer that the Steelers can't match. The New England Patriots, San Francisco 49ers, Baltimore Ravens and Cincinnati Bengals have been mentioned as teams that would be interested in Wallace.

Pittsburgh would be less vulnerable if it uses the franchise tag on Wallace, but that would cost the Steelers $9.6 million for this season. The Steelers saved $8 million in cap space Thursday by restructuring quarterback Ben Roethlisberger's contract, a league source told ESPN NFL Insider Adam Schefter. Pittsburgh was an estimated $8 million over the cap before reworking Roethlisberger's contract and will have to trim even more space in order to use the franchise tag on Wallace.

Colbert said the Steelers would use the first-round tender at the very least and mentioned that the franchise tag remains a possibility.

"Having a great player like Mike Wallace is not a dilemma," Colbert said. "We're going to do everything we can to make sure that Mike Wallace remains a Pittsburgh Steeler and I think that's Mike's belief as well. Usually when you have two parties that share the same goal, it's easier to achieve that goal."

Wallace, taken by the Steelers in the third round of the 2009 NFL draft, acknowledged on Wednesday that he might not be playing for Pittsburgh this season.