Plouffe has been basically average compared to MLB 3B OPS in 2014 and 2012, and was ~5% below average in 2013. But average doesn't mean permanently acceptable -- the average includes a lot of bad players (injury replacements, backups, rookies, over-the-hill vets). I think it is better to look at ranks, with a lower PA threshold than batting title qualifiers to account for injuries, rookies, etc. With 300 minimum PA (or 200 so far in 2014), Plouffe has ranked 23, 25, 21 among 3B at Fangraphs going back to 2012. He's pretty clearly in the bottom 25-30% of MLB third basemen offensively. Funny you mention Middlebrooks because he lost his starting job from June into August last year, lost it again during the playoffs, and finally lost it yet again right away this season. And Plouffe doesn't make much, but it's not "no money" anymore -- $2.3 mil this year, probably $3-4 mil in arbitration the next couple years. That said, I don't think he should be replaced now, or even spring 2015, but he's really just a patch to Sano at this point. And I doubt his bat/salary would play in the corner OF regardless of his glove.