This unexpected deal actually makes a lot of sense.
The Rockies and Blue Jays surprised everyone by swapping shortstops as well as veteran reliever LaTroy Hawkins (heading to the Blue Jays) and prospect pitchers Jeff Hoffman and Miguel Castro (Going to the Rockies). This reminds me of another trade the Blue jays made when they upgraded their third baseman from Brett Lawrie to Josh Donaldson in a trade with the A's in which they also had to give up three young players including MLB.com's #85 prospect Franklin Barreto. This time they are upgrading their Shortstop from Jose Reyes to Troy Tulowitzki. The Blue Jays side of these trades is a very clear gain from a left side of the infield that from 2013 until now has been worth a total of 32.3 WAR, and they traded away Reyes and Lawrie worth only 11.8 WAR. Seeing the Rockies and A's side is a little more difficult. I already analyzed the Josh Donaldson trade from both sides here, so we can focus on why the Rockies who were willing to trade their homegrown five time all-star who I would argue when healthy has been the best shortstop in the majors. The rockies needed this trade because although they do have a major loss in hitting ability at the shortstop with close to no change in payroll it gives them a needed increase in pitching potential with prospects Jeff Hoffman MLB.com #69 prospect who will be a phenomenal pitcher as long as he recovers well from Tommy John, and Miguel Castro with a great fastball sitting in the mid-upper 90s. The blue Jays were willing to spend big on pitchers to get Tulo because they already have numerous other young pitchers including 20 year old closer Roberto Osuna who currently has a 2.23 ERA, MLB #12 overall prospect Daniel Norris, as well as top young starting pitchers Drew Hutchison, Aaron Sanchez, and Marcus Stroman. This trade also brings them a veteran reliever in Latroy Hawkins ready to share his experience and advice with these young pitchers. This trade uses the Blue Jays surplus of pitching to fill a need for the rockies as well as supplying the Blue jays with another upgrade to the left side of their infield. Giving the Rockies a hopeful future and the Blue Jays one of the best shots at the division title that they have ever had in the modern AL East (they have not won the division since it became a five team division and the Central was added).