This makes sense. I still think the Twins should have sprung for what the Cubs did (a full-strength Baker might be worth a qualifying offer for draft compensation, which is like a really expensive team option with a consolation prize) but a team option is the traditional give-and-take of a one year make good deal with a slightly higher than expected guaranteed base.

http://www.startribune.com/sports/twins/blogs/179136771.html

Baker agrees to sign with the Cubs; Twins wanted him back, but 2014 option was the sticking point
Posted by: Joe Christensen under Twins pitching Updated: November 13, 2012 - 11:50 AM 74 commentsprint

The Twins had interest in re-signing Scott Baker, and the righthander had interest in coming back to Minnesota, but negotiations reached a sticking point before Baker agreed to sign with the Cubs on Tuesday.
Baker's new deal with the Cubs will pay him $5.5 million guaranteed, with an additional $1.5 million in incentives, a person familiar with the contract confirmed.

Baker missed all of last season while recovering from Tommy John ligament-replacement surgery in his right elbow. The Twins declined a $9.25 million option for next year, letting him become a free agent.
Two weeks ago, Baker said the sides were making progress toward a new deal. But, according to the person familiar with his new contract, the Twins insisted on the deal including an option for 2014. Baker, 31, wanted a deal that would let him re-establish his value and then test the market again next fall.

In the end, the Twins weren't really that close, so Baker is heading to the Cubs. He went 63-48 with a 4.15 ERA in seven years with Minnesota.

The Twins are moving forward with Scott Diamond as the only starter penciled into their 2013 starting rotation.