CHICAGO (CBS) — Ahead of their home opener, the Cubs have placed first baseman Anthony Rizzo on the 10-day disabled list, due to a back problem.

To take Rizzo’s spot on the active roster, the Cubs have called up infielder/outfielder Efren Navarro from Triple-A Iowa.

Rizzo has not played since Thursday night against the Brewers, because of tightness in his lower back. He will miss the upcoming series against the Pirates and Braves, but is eligible to return for the start of next week’s home series against the Cardinals.

The first baseman was slumping before his injury, batting only .107 with one home run and three runs batted in through his first six games.

Navarro, 31, was signed to a minor league deal in the offseason. He has spent 12 years in the minor leagues with the Angels, Mariners, Cardinals, and Tigers systems.

This season with Iowa, he was batting .250 in three games, with three RBI.

In his minor league career, he is batting .295, with 282 doubles, 65 home runs, and 607 RBI in 1,245 games.

In 153 career games in the majors since 2011, he is batting .243 with three home runs and 22 RBI. He’s played 87 games at first base and 44 in the outfield.