The Cardinals are aggressively trying to re-sign some of their own free agents, but consummating deals might be difficult with free agency due to start in less than three weeks, General Manager Steve Keim told Arizona Spots 98.7 FM on Friday morning. “As it gets closer to free agency, some players prefer to try and test the market, which we understand, it’s a business,” Keim said. Team officials have had positive talks with the agent for outside linebacker Chandler Jones, but no deal is imminent. Keim reiterated that the club will use the franchise tag on Jones if a long-term deal can’t be reached. The club also has been in serious negotiations with the representative for safety Tony Jefferson, according to an NFL source. The Cardinals went 7-8-1 last year, and Keim promised to be aggressive in trying to shore up weaknesses. That includes upgrading special teams, a problem area throughout last season. “It wasn’t good enough,” he said. “There wasn’t any secret to that. It was unacceptable and there is no doubt that has to change. So whoever our kicker is, our punter, our long snapper those guys have to step up and answer the bell.”