4:56pm: The Orioles aren't the team that has offered Balfour a vesting option, tweets Encina.
3:40pm: Dan Connolly of the Baltimore Sun reports that the Orioles are one of three teams that has made a two-year offer to Balfour. One team's offer contains a vesting option for a third season, he adds. Connolly isn't sure which team has offered the vesting option, but he gets the sense that it's not the Orioles (Twitter links).
1:45pm: The O's prefer Balfour on a two-year deal, and one other club is still in the mix at this time, tweets Heyman.
12:56pm: Years are the main sticking point in negotiations with Balfour, tweets Eduardo A. Encina of the Baltimore Sun.
THURSDAY, 11:54am: The Orioles are confident that they can sign Balfour, tweets Ken Rosenthal of FOX Sports.
WEDNESDAY: The Orioles have an offer out to reliever Grant Balfour and others as they try to fill four holes in their lineup, writes Jon Heyman of CBSSports.com. The O's also have an offer out to John Axford, a source tells Jon Paul Morosi of FOX Sports (on Twitter). Heyman also notes that Baltimore has talked to Nelson Cruz's agent, but a source tells Eduardo A. Encina of the Baltimore Sun (via Twitter) that the club hasn't made an offer to him.
Heyman writes that the O's are also in on an unnamed starting pitcher. Baltimore also has to address holes at closer, left field, and at DH. Balfour is their top choice to replace Jim Johnson as a closer with Axford and Chris Perez believed to be secondary options.