The 32-year-old Turner is coming off a career year with the Los Angeles Dodgers, who took a chance on him back in February of 2014 and signed him to a minor league contract. Turner achieved personal bests in 2016 with 34 doubles, three triples, 27 home runs, and 90 runs batted in and displayed defensive promise, a trait the Cardinals collectively lacked.
Turner is one free-agent that is on the hot market in the off-season, along with Kenley Jansen and Aroldis Chapman. As Morosi notes, St. Louis may have to trade Jhonny Peralta for a match with Turner to make sense.
The Cardinals' current roster construction would not seem to indicate a need for Turner, though a trade of Peralta would open an infield spot alongside Matt Carpenter (first base), Kolten Wong (second base) and Aledmys Diaz (shortstop). Turner also provides positional flexibility having played all at all the bases at some point, though mostly third.