The deal is worth up to $3 million, according to a league source.
Even though Waters' salary will be guaranteed if he's on the opening-day roster, the Cowboys don't expect him to play in Sunday night's opener against the New York Giants. A source said his conditioning level would be a potential concern, as is the fact that he is not familiar with the other members of the offensive line or coach Jason Garrett's offense.
On Wednesday, Garrett was non-committal about Waters playing Sunday.
"He's been a very good player for a long time as a protector, as a run-blocker," Garrett said. "He's big, strong, physical, athletic. He plays with the right kind of demeanor. He's been that way a long time. Ask anybody that ever evaluated him in-house or from afar, and everybody says that.
"He did miss training camp prior to playing in New England [in 2011], but he had played the previous season, so that would be one difference. He didn't play last year, so we have to respect and understand that. But again, we think he's in relatively good shape. Let's see what kind of progress he makes over the next few days."
The Cowboys made being more physical up front their first priority in the offseason, using a first-round pick to draft center Travis Frederick, who carried a second-round grade on the Dallas draft board. The Cowboys also want to protect Tony Romo after the quarterback was sacked a career-high 36 times each of the past two seasons.
Starting left guard Ronald Leary did some individual drills Monday after recovering from minor knee surgery. Leary said he feel better Tuesday when he showed up to Valley Ranch for treatment on the players' off day.
ESPN NFL Insider Adam Schefter, ESPN.com's Todd Archer and ESPNDallas.com's Calvin Watkins contributed to this report.