Dodgers place J.D. Martinez on the injured list with lower back tightness

LOS ANGELES — The Dodgers placed designated hitter J.D. Martinez on the injured list on Friday after he missed all three games against the Pirates in Pittsburgh with lower back tightness.

Martinez swung in the batting cage to test his back before Friday’s game against the Cardinals.

“I’m trying to play it smart, to see what I can do, see what hurts, see what doesn’t,” Martinez said. “Doing my exercises for core strength, and just try to avoid as much pain as I can while the inflammation dies out.”

The roster move was backdated the allowable maximum of three days, to Tuesday, meaning the earliest Martinez could return is next Friday, May 5, when the Dodgers open a three-game series against the Padres in San Diego.

“There’s got to be pronounced improvement, to feel that losing four of five days, that we can bet on the last four to five days,” manager Dave Roberts said Friday, before the Dodgers officially made the IL move. “If we don’t think that’s the case, we’re not going to lose the days we’ve already banked.”

Martinez said he first felt back soreness running out of the batters box last Sunday against the Cubs at Wrigley Field.

“I wanted to stay in because of [Muncy]. I didn’t want to take the bat out of his hands. It was a close game. Then I hit a home run off [Marcus] Stroman and felt it again,” Martinez said Friday at Dodger Stadium. “I probably should have said something but didn’t.

“Honestly, I was just being dumb, trying to be a hero. Trying to weather it out. I should have spoken up sooner, it probably would have saved me.”

The back soreness got worse for Martinez on the flight from Chicago to Pittsburgh, where he missed all three games.

Losing Martinez is the latest blow to a Dodgers offense that during the series at PNC Park was without its usual third, fourth, and fifth hitters in the lineup. Los Angeles scored only 11 runs in three games against the Pirates, including three runs over the final two games, both losses.

The good news is the Dodgers activated Max Muncy on Friday off the paternity list after missing three games for the birth of his son Wyatt. Muncy leads the majors with 11 home runs, an 1.129 OPS, and a .718 slugging percentage. He won National League player of the week Monday following a stretch of 10 home runs in his previous 13 games.

Will Smith was activated as well on Friday after missing 13 games on the concussion injured list. Smith will be the designated hitter in Friday’s series opener against the Cardinals.

“We’re not completely whole, but it does feel good to have the guys we intended on being in the lineup every day, and feel really good about them,” Roberts said Friday.

Martinez is hitting .250/.306/.534 with four home runs, nine doubles, two triples, and 15 RBI this season. He started each of the first 23 games before missing all three games in Pittsburgh.

“He’s a guy that swings a lot, and for him to not be able to do that is certainly telling,” Roberts said Thursday.