Chicago Cubs second baseman Nico Hoerner was placed on the 10-day injured list Wednesday with a strained left hamstring suffered in Tuesday's win over the Pittsburgh Pirates.

Hoerner, 24, had been a big part of the Cubs' success in May. He was hitting .338 and playing high-caliber defense.

The injury occurred as Hoerner was running toward first base on a ground ball. He grabbed his left hamstring as he hit the bag, then went to the ground in obvious pain.

Rafael Ortega was recalled from Triple-A Iowa to take his place on the roster.

In addition, first baseman Anthony Rizzo is being held out of Wednesday's game against the Pirates with low-back tightness. Kris Bryant is playing first base.