Boone not worried about slow start by Donaldson

BALTIMORE — Josh Donaldson has a team-high 13 strikeouts and an ugly OPS of .454, not exactly what the Yankees expected when they made him the centerpiece of the trade that sent Gary Sanchez and Gio Urshela to Minnesota.

“I think he’s on the verge,’’ Aaron Boone said of Donaldson before the Yankees opened a series against the Orioles on Friday at Camden Yards with a 2-1 loss in 11 innings.

“I’m not worried about him,’’ the manager said. “If we keep him healthy, he’ll have a big year for us.”

Donaldson went 1-for-5 with a single and two more strikeouts.

In an effort to try to keep Donaldson on the field, he has been used as the DH — something he did again on Friday, with DJ LeMahieu at third base and Giancarlo Stanton in right field for a second straight game.

➤ Jordan Montgomery looked just fine after suffering a bruise on his left knee when he was struck by a 102-mph comebacker off the bat of Boston’s Xander Bogaerts in his first start of the season.

The left-hander pitched five shutout innings on Friday, limiting the Orioles to three hits in his 71-pitch performance that was wasted because of the offense’s struggles.

➤ Aaron Judge wasn’t in the lineup for the first time of the young season on Friday.

Boone said it was a planned day off.

Judge pinch-hit for Isiah Kiner-Falefa in the top of the 10th and grounded out.

➤ Boone said Luis Severino had “good soreness” coming out of Thursday’s start, another bit of encouraging news after the righthander tossed five scoreless innings on Thursday. Severino hasn’t had any physical issues since his entire arm was sore following his second Grapefruit League start of the spring.