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v. Third-person singular simple present indicative form of underperform.

"Now, I happen tot hink that Sweeney's contract was a bit too high at the time, but the Twins paid pretty much what Mauer would be worth on the open market … so if he "underperforms" even just a bit each year … say, he's only a 5.5 win player at the moment rather than 6.5, the Twins are going to be hurting."

overperform   

underperformed    underperforming    underperforms   

perform    do   

underperformer    underperformance