Please welcome the guy who's about to become the newest Mariner starting pitcher.
There's nothing not to like about this deal - it's cheap, it's short (one year, 2008 option), it won't result in a lost draft pick, and it's going to an arm who's only 80.1 innings removed from a three-year stretch in which his FIP was just over 4.00. Thomson wasn't much to look at in 2006, but he was dealing with finger and shoulder issues that cut into his effectiveness. After an offseason of rest, he should be ready to go by ST, and as long as he's healthy there's no reason why he shouldn't supply the Mariners with league-average performance for a very reasonable cost. I'd say the odds are pretty good that he finishes the year with a better ERA than Gil Meche, who's going to fetch a metric assload of money.
There are no guarantees that Thomson's going to stay off the DL all year; if there were, he wouldn't be coming so cheap. Bargain players are bargains for a reason, after all. Still, Thomson looks pretty safe, and even if he tanks, the commitment is small enough that cutting our losses wouldn't be a big deal.
This is a smart move. Thomson's better than Tomo Ohka, a perfectly serviceable #4 who leaves the Mariners with only one hole in the rotation that needs to be filled. While other GM's are falling all over themselves to sign guys like Meche, Lilly, Padilla, and Eaton, Bavasi outmaneuvered them all and landed a similar pitcher for a fraction of the price. Thomson may not work out in 2007 after all, but the same goes for each of the other four; the only difference is that, were that the case, the Mariners wouldn't be on the hook for another two or three years of salary. There's minimal risk here.
John Thomson has his problems, but as far as reliable rotation filler goes, I don't know that we could've done any better with the players available. I like it.