In other words, Nava could still be traded this offseason.
Nava has been with the Red Sox organization since they spent $1 to purchase his rights from the independent Chico Outlaws in 2008.
An unheralded prospect, Nava got a surprise callup to the Major Leagues on June 12, 2010. That day, he made Major League history, becoming just the second player to hit a grand slam on the first pitch of his career.
Nava has played in 395 games for the Red Sox, hitting .273 with a .362/.398/.760 slash line.
Tazawa is expected to again be a key setup man in front of closer Koji Uehara.
Boston's 40-man roster is currently full.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.