Meh. I actually want to disagree with this. Tavarez was a mediocre starter at best, but a mediocre starter was all he was asked to be.
In the wake of the decision to keep Papelbon at closer and with news that Lester's recovery was taking time we had 4 starters to break camp with that year so they threw Tavarez into the fire, and he filled in well enough to not be a dumpster fire, which considering that the guy was basically a mediocre garbage time reliever in the first place being asked to play a role WAY above his own head, for a team that was contending (and would win) a World Series that year, I feel that he gave us all one could reasonably expect and he merits an official "exceeds expectations" rating for me for his performance in 2007.
I mean if he was a regular starter that would be one thing, he went 7-11 with a 5.15 ERA, that wouldn't be a great outcome for a guy who's used to starting 20 or more games a year. But this is a junktime reliever thrown into the role out of desperation. We didn't exactly expect to be fielding Sandy Koufax when we moved the guy to the rotation on an emergency basis, and at the very least he kept the 5th starter role from becoming a crisis, which is all he was expected to do by team leadership. A guy who met or exceeded the expectations the team placed on him and who it took a guy getting cancer to ever start in the first place, probably doesn't belong in the "Worst. Pitcher. Ever." conversation.
Besides, the guy was fun to watch with his eccentric style and weird decision making. You could tell he was having fun, which made him fun to watch. And he did give us some great games, like the CG against Toronto.
Also, just the year before we had a fill in who had to start regularly and was far, FAR worse. Kyle Snyder.
Rudy Seanez was worse than both, and Daniel Bard is not a candidate for bad reliever much less worst reliever when the dude had a couple stellar years. He sucked after his shoulder fell off but I don't even care about that in a conversation like this because Bard was too good for us when he was good.