The Cardinals extended the contract of Paul DeJong, last year's ROY runner-up for 6 years, plus two team options. It's the longest/most expensive extension ever for a player with less than one year of service time (108 games, 443 plate appearances).
Normally I would say this is premature, but look at the track record of players the Cards have extended before their free agency period: Molina, Wainwright, Shumaker, Garcia, Motte, Craig, Carpenter, Walden, Lynn, Jay, Wong, Piscotty and now DeJong. After a solid streak, they hit a bit of a slowdown, but dealt Craig before he imploded (or perhaps caused his implosion), I could have told them Walden was a mistake, and it's too early to tell on Wong, but just about everything worked out (recognizing that Piscotty wanted to move home to be closer to his sick mother).
I would love to know how that franchise assesses talent. One other thing to point out - none of them were represented by Scott Boras.
