Pedro Strop's numbers show dangerous similarities to Carlos Marmol

When Pedro Strop came in the game Wednesday afternoon against the Cardinals the Cubs were up 3-1. By the time the game was over, the Cubs would lose 4-3, with Strop responsible for a pair of those runs.

There is no doubt that Strop has the stuff to be electric. When he’s on, he’s one of the best set-up men in the business. But when he’s not, Strop is almost unusable.

The issue is a familiar one for the Cubs. Strop’s slider is deadly, but when it’s left around the plate the reliever has been getting pounded.

A slider that batters can’t touch outside of the zone, but gets hammered inside the zone should sound eerily similar to the complaints of a former Cubs reliever, Carlos Marmol.

At his prime with the Cubs, Marmol was unhittable. Batters would flail at the plate, badly missing his slider, before being blown away by a fastball.

But by the end of his career, opponents learned a valuable lesson. Just wait, Marmol won’t put a ball in the strike zone unless it’s hanging.

During his best years, batters would make contact with less than 50 percent of pitches they put a swing on outside of the strike zone. Inside the zone, however, that number was consistently over 75 percent.

By the time Marmol left, his strikeouts had fallen off while walks were steadily climbing. Even more concerning, his earned run average had skyrocketed.

Strop doesn’t have the pressure put on him that Marmol had. However, it should be a concern for the Cubs brass.