Maybe the Cardinals shouldn't have traded away Oli Marmol's enemy after all

Last offseason, the St. Louis Cardinals traded Tyler O'Neill to the Boston Red Sox. O'Neill was coming off yet another injury-plagued season in St. Louis and didn't have a clear role with the team moving forward. So, they found a new home for him in Boston, and since his arrival in Beantown, the 29-year-old has taken off. The former Cardinals slugger is hitting .252 with 16 home runs, 31 RBI and an .839 OPS.

O'Neill's resurgence once again raises questions about the Cardinals organization. They've been burned once again for trading an outfielder, and it goes to show that maybe St. Louis didn't properly evaluate the talent within their organization.

Tyler O'Neill trade has come back to haunt the Cardinals

Granted, O'Neill had dealt with various injuries during his tenure in St. Louis. There also was a slight rift between him and manager Oli Marmol following a public spat early last season. The Cardinals also had a serious logjam in their outfield, and they needed to clear it.

So, it's understandable why they might have thought trading O'Neill wasn't such a bad idea. However, the trade has come back to haunt them, not unlike the trades of Randy Arozarena and Adolis Garcia. Perhaps the biggest mistakes they made were selling low on him and also not properly evaluating the talent within their system.

It's happened too many times to be a mere coincidence. The Cardinals have traded yet another outfielder who ended up finding his groove with a new organization. Clearly, there's an issue with the team's player development system and the way the organization evaluates talent. At the very least, the Cardinals could have sold a little higher on him and gotten something more valuable in return.

Nick Robertson, a reliever they acquired in that deal, is currently on the injured list, and right-hander Victor Santos remains in the minor leagues. The Red Sox are bearing the fruits of this deal, while the Cardinals find themselves in a similar predicament, and still with too many outfielders.

O'Neill is a free agent at the end of the year, so the Cardinals could offset this in the offseason by signing him back. But for now, they're on the wrong end of yet another lopsided trade.