The St. Louis Cardinals called up a key player from the Jack Flaherty deal, creating a path to winning the trade.

When John Mozeliak traded away Jack Flaherty (and more) at the deadline, he cited his goal as creating pitching depth. Flaherty is set to enter free agency after the season, and did say he would be open to a St. Louis return.

However, his comments about the attendance at Camden Yards rubbed certain Cards fans the wrong way.

The trade itself was initially deemed a win by the Orioles, thanks to Flaherty's impressive first two starts for Baltimore. I wrote about the initial changes the O's pitching coaches made to Flaherty's approach a few weeks ago:

"Flaherty's start saw a bump in his fastball velocity by over a full MPH. Perhaps the most noticeable change, though, was how often Baltimore called on Flaherty to use his cutter. He threw the pitch 28 percent of the time, which was a season high, and it was very effective for him."

In his last start against the San Diego Padres, Flaherty looked far more human, though, giving up seven runs in three innings of work. It wasn't pretty.

Who won the Cardinals-Orioles trade for Jack Flaherty?

We initially grades this trade as a win for the Cardinals, as they were able to acquire two top-20 prospects from a strong Baltimore farm system. As for the Orioles, while Flaherty is a nice get, he is not the ace this team desperately needs to make a World Series run. That'll likely come in the offseason.

On Monday, St. Louis called up Drew Rom to make his first start as a Cardinal. That could turn this trade in the Cards favor even further.

Rom will face a Pirates team that has been struggling of late. Mozeliak has said he wants to see what he has in this young pitching staff, especially with only two regular starting pitchers under contract heading into next season.

Should Rom turn into a starting rotation-level pitcher, then consider this trade a home run for the Cards. Prieto is just the cherry on top.