BOSTON -- The Red Sox offered reliever Mariano Rivera a two-year, $30 million deal and were prepared to non-tender closer Jonathan Papelbon, according to a baseball source with direct knowledge of the negotiations.

Rivera turned down the Red Sox to return to the Yankees, who offered the same money as Boston. Rivera's pending agreement with the Yankees was first reported by the New York Daily News.

The Red Sox on Thursday night tendered a contract to Papelbon, who was paid $9.35 million last season and is arbitration-eligible, which will drive his salary into eight figures. Papelbon is a year away from free agency.

By any measure, the 30-year-old Papelbon had the worst season of his career in 2010. His 3.90 ERA was more than a full run higher than in any of his previous five seasons in the majors, and his eight blown saves were also a career high.

On Thursday night the Yankees and Rivera's agent, Fern Cuza, were putting the finishing touches on Rivera's contract.

"There are a lot of steps in the process, from agreeing to something in principle to getting the physical done," Yankees general manager Brian Cashman said Friday morning when asked if the Rivera deal was done. "Until all those things are covered, I'm not in a position to say."

The Yankees could announce that the deal is official as soon as Friday.

Andrew Marchand of ESPNNewYork.com contributed to this report.