Haren is must-sign for the Red Sox. There are concerns about his medical sure, but the Sox need the pitching depth.
For a guy who has a bad back he had a good September, which is important, 3.07 ERA, 0.99 WHIP, 29 1/3 IP, 23 K, 5 BB, 5 starts. I'll take that as a good indicator that he was feeling better at the end of last season and therefore it makes him worth a look.
Why not throw 1-year $10M at him with $7.5M in performance bonuses? That should get it done. If we can afford to budget $8.1M for two backups who are unlikely to do diddly to improve the Red Sox next season (D Ross, & J Gomes) why can't we guarantee Haren $10M? He just might be an ace. At worst he might reproduce 2012 which wasn't all that bad, it just wasn't Haren good.