It seems highly unlikely that Nathan will be able to make it through the 2010 season, which is unfortunate considering how valuable he has been to the Twins over the past six seasons. Regardless, the Twins are monitoring Frasor in the event they need an extra arm in the pen.
The Cubs could force the Twins' hand on this trade as they are also talking to the Jays about acquiring the Chicago native. The Cubs will be without Angel Guzman for the 2010 season, barring a miraculous recovery, and would like another arm to bridge the gap to the later innings.
Frasor posted a 2.50 ERA in 61 appearances for the Blue Jays last season, striking out 56 and walking 16. The 2009 season was certainly Frasor's career best, so the Jays likely won't just dump him for a low level prospect. And teams looking to add him aren't unloading a major league ready anything for a reliever with a collective 4.36 ERA from 2006-2008.
One NL executive reminded me that the Padres shopped Heath Bell this offseason and for most of last season, and he could emerge as an option for the Twins as a full-year option or half-year rental. The Twins are expected to be in the AL Central race all season, and adding a closer like Bell could salvage the bullpen and maybe even there season.