According to Ken Rosenthal, the Rockies and Rays have discussed a trade, although it doesn't seem like the talks went far.
Sources: #Rockies spoke to #Rays about OF for SP swap. TB already has Kiermaier-Souza-Jennings-Guyer. More likely to seek prospects for SP.
— Ken Rosenthal (@Ken_Rosenthal) December 17, 2015
Colorado has reportedly put Carlos Gonzalez and Charlie Blackmon on the trading block, but with Tampa's already crowded outfield, there isn't a clear fit.
The Rockies do however have more than a few prospects that they could potentially ship to the Rays in exchange for a starting pitcher. Via Baseball America, Colorado's top ten consists of Jon Gray, David Dahl, Brendan Rodgers, Jeff Hoffman, Ryan McMahon, Kyle Freeland, Tom Murphy, Trevor Story, Antonio Senzatela, and Raimel Tapia.
Of those players, Gray, Dahl, Rodgers, and Hoffman are likely the most untouchable. However without knowing who the Rockies might want from the Rays, it's nearly impossible to try and guess at a potential package.
An educated guess would be that Colorado is interested in Jake Odorizzi, not only because he's controllable through the 2019 season, but also because his name has come up a number of times this offseason. As of now, there's nothing imminent going on between the two clubs, but with multiple teams already interested in Odorizzi (and now potentially the Rockies), his price could begin to skyrocket.