According to Susan Slusser of the San Francisco Chronicle:
Shortstop Bobby Crosby becomes the A's backup middle infielder with the Orlando Cabrera acquisition, but there could be some interest in him before the spring is over - including from the Cubs, according to one source. One of Chicago's top scouts was watching Tuesday's game and is known to have been a fan of Crosby in the past.
The biggest hurdle for a Crosby trade, of course, is the $5.25MM owed to him in 2009. I spoke to a source familiar with the Cubs' thinking, and he said there's "nothing to it." He said the Cubs scout was watching the A's as part of general coverage of all teams.