Why? Among players starting at least 400 games in the outfield over the past four regular seasons, Martinez ranks third in OPS+, behind only Mike Trout and Giancarlo Stanton.
Yes, Martinez is ahead of Bryce Harper on that list.
MLB team executives have expressed concern in the past about Martinez's defense. A Lisfranc sprain in his right foot, which kept Martinez out of Detroit's first 33 games this season, exacerbated those worries. But Martinez's play in right field improved after the trade -- to a league-average level -- likely because of better positioning by the analytically inclined D-backs.
Here's a look at five possible landing spots for Martinez this offseason:
Giants: Martinez and San Francisco might be the most logical pairing of any free agent and team this winter. In a record-setting season for home runs across the Major Leagues, the Giants finished last with 128. Martinez hit 45 by himself, third most in the Majors. The Giants have lacked reliable production in left field for years and don't possess a proven in-house solution at the position.
Angels: Martinez's viability in Anaheim is wholly contingent on Justin Upton. If Upton decides to opt out of his contract, Martinez becomes an excellent fit alongside Trout. If Upton stays -- or if the Angels acquire Stanton in a blockbuster deal -- Martinez can cross off the Angels from his list of destinations.
Cardinals: The Cards are known to be looking for a big bat this winter. If they're stymied in their efforts to acquire Stanton or Josh Donaldson via trade, Martinez could be the top option remaining on their wish list. The Cardinals likely would need to move an existing outfielder -- Dexter Fowler, Randal Grichuk or Stephen Piscotty -- to clear a spot for Martinez.
Red Sox: At first glance, the fit for Martinez in Boston is difficult to envision. The Red Sox already have three young outfielders, and Hanley Ramirez accounts for a high percentage of at-bats at designated hitter. But the Sox could trade center fielder Jackie Bradley Jr. for a starting pitcher, move Andrew Benintendi to center and sign Martinez to play left while the superb Mookie Betts remains in right.
D-backs: Because he was traded midseason, Martinez cannot receive a qualifying offer, but the 30-year-old has given his most recent employer every reason to retain him -- from the world-class power and improved defensive play to his perpetually upbeat clubhouse presence. Yasmany Tomas' inconsistency and injury history suggest Arizona will need to find another veteran outfielder -- whether Martinez or someone else -- to play alongside A.J. Pollock and David Peralta.
Jon Paul Morosi is a reporter for MLB.com and MLB Network. He has also covered baseball for FOX Sports, the Detroit Free Press, and the Seattle Post-Intelligencer. This story was not subject to the approval of Major League Baseball or its clubs.