The Rangers have lost three straight games and are now four games behind the Cleveland Indians and Oakland A's for the American League's second wild card spot. It would make sense for the club to entertain trade offers for every player mentioned in the reports as most of them will be free to walk away after the season.
The return for Forsythe and Cabrera would obviously not be very substantial (likely the typical "player to be named later" type). Despite Choo's solid play, his value remains low due to his large contract. He is, however, entering the final year of his deal next season.
Santana is a player Texas would likely want to keep for the foreseeable future due to his age and performance this season. Look for them to keep him around and attempt to re-sign him next season.
Pence is another player the Rangers would likely want to keep around for the rest of the season and beyond due to his play and his ties to the community. Pence, an Arlington native, is having a resurgence year with Texas and would be a player the fans would like to see on the club as they head into the new ballpark next season. Texas could always trade Pence for something before the trade deadline and attempt to bring him back next season.