Headley, who won a National League Gold Glove Award in 2012, is still widely considered to be a strong defensive third baseman. According to Fangraphs.com, Headley entered Tuesday tied for fifth in the Majors with seven defensive runs saved, a statistic used to measure the number of runs a player saves or costs his team on defense relative to an average player.
However, Yankees general manager Brian Cashman did not expect Headley to serve as anything but a serviceable third baseman.
"I think there's some confusion on the metrics about what he really is," Cashman said. "Our scouts have him as an average third baseman."
One thing is for sure -- Headley is certainly a defensive upgrade over those who manned the position before him.
Yankees third basemen this year have a combined for a DRS score of -1, including -3 for Yangervis Solarte, who was traded to San Diego as part of the deal. Solarte made the Yankees out of Spring Training, and a hot start at the plate earned him the majority of the starts at third base in the first half, but his defense remained subpar.
The Yankees have used a variety of utility men to fill the role, including Kelly Johnson and Zelous Wheeler, who started at third on Monday and Tuesday. Manager Joe Girardi said Headley will be the team's everyday third baseman for the rest of the year.
"He's a guy that's used to the position and understands the position," Girardi said. "I think our guys have played there better as of late, but we'll have some consistency there, which I think will be good."
There are some numbers to back up Cashman's claim. Headley has nine defensive runs saved since 2012, which is tied for 13th among third baseman, and that includes seven this year. During his Gold Glove season in 2012, Headley's DRS was minus three.
He led the Majors in the month of May this year in that category with nine, but has a minus two during the rest of the year.
But the Yankees recently acquired right-hander Brandon McCarthy, who is known for inducing many ground balls, as is right-hander Shane Greene. The club's reliance on a ground-ball staff makes Headley seem that much more valuable.
"The upgrade was really comparing Chase and where we project him currently, rather than what April, May and June were looking like," Cashman said. "It's as simple as that. We feel like we're at least getting an average everyday Major Leaguer at that position and maybe more.
"We'll see. You want to support your pitching staff, especially pitchers like Brandon McCarthy, with real quality defense. Your infield has to be strong the day that a guy like that pitches."