The D-Backs are apparently facing some salary constraints, and might not be willing to offer a competitive deal to RJ, who made $15 M last year.  The Cubs have strong starting pitching, but if they lose Dempster and don't trade for another starter, are they comfortable with both Marshall and Marquis in the rotation?  IMHO, Johnson could sign a one-year deal for around $8 M plus incentives for games started. 

Is the Big Unit too much of an injury risk in a rotation that already has Harden?  Would you (playing GM) rather sign  Derek Lowe for 3 years than Johnson for 1?  Would Cub fans care about Johnson approaching 300 wins, or is Wrigley going to sell out in April and May anyway? 

Stats from this year: 11-10, 3.91 ERA, 173/44 K/BB in 184 innings. 

He made only 10 appearances in 2007 with back troubles, but was quite effective and healthy in 2006.