The seven-year, $60 million extension, first reported by ESPN Deportes, will become official once it's drafted and the contract language is ironed out, sources told ESPNChicago.com's Doug Padilla.
Hendry, who was fired from the Cubs last year and is currently a special assistant to New York Yankees GM Brian Cashman, joined "The Waddle & Silvy Show" on ESPN 1000 on Wednesday and complimented the job done by Cubs president Theo Epstein.
"I don't get into the ins and outs and haven't asked anybody what the details are, but I think obviously it looks like to me to be one of those mutual positive things where Theo has probably done a good job of getting a deal where if Starlin stays healthy and performs up to reasonably what he should, then it's a good hometown deal," Hendry said. "At the same time, Starlin gets lifetime security with a first deal, and then still will be under 30 when that deal is over to do another one.
"I think that's what those deals for young, marquis players are supposed to be, and it looks like from the outside, a good marriage for both."
The 22-year-old Castro has made the last two All-Star teams and is one of the cornerstones of Epstein's rebuilding project. It's the type of project Hendry may not have felt comfortable undertaking considering the Cubs were sold during his tenure and he was trying to build a winning team to make it as attractive to buyers as possible.
Hendry led the Cubs to four postseason berths and had them five outs away from the World Series in '03 before the team lost Games 6 and 7 of the NLCS to the Florida Marlins at Wrigley Field.
"(Epstein's rebuilding is) a path that will be good down the road, and you'll benefit from even things like when you bring up guys like (Brooks) Raley and (Chris) Rusin and people that are young and inexperienced," Hendry said. "All those starts now and all the playing time these young kids are getting will benefit shortly in the near future, not the long future. I think you'll see steady improvement (in the near future)."