BOSTON -- The stunning slump of J.D. Martinez, which has basically lasted all season, has been caused mainly by bad habits the slugger is having a hard time erasing, according to hitting coach Tim Hyers.

“He’s worked and been diligent the same way he’s been in the past. I know this kind of sounds like an excuse, but he fell into some bad habits,” said Hyers. “Right now, he’s trying to deal with his back side. We call it his back hip. He just jumps off his back side and he’s creating some length in his swing on the back side, and he’s just late to fastballs. I know he’s working on it.”

There have been sporadic teases these past two months of Martinez regaining his form, but they typically last just a day or two. There are now just seven games left in the season.

In a 60-game season, perhaps Martinez put too much pressure on himself to get out of his slump.

“He was building a new routine and with a shortened season and how things add up, yes, it’s going to knock his confidence down and he starts to have doubt,” said Hyers. “And he’s a competitor and he’s wanting to put the team on his shoulders and produce for the fans and for this organization, and you try a little too much. I think that’s [what] some of the mechanical flaw is: I’m trying to hit it a little farther. I’m trying to hit the big home run, and you come out of your mechanics. You’re not relaxed. Trying to do too much, and he gets big and misses a few fastballs he should hit, and it kind of rolls downhill after that.”

Martinez did get two hits in Saturday’s loss to pull back above the Mendoza line, and he homered in Sunday's victory off Yankees catcher Erik Kratz, who was pitching in the Red Sox's rout of their rivals. The dropoff has been somewhat startling, though, for a player who hit above .300 in five of the previous six seasons.

“Last night was a lot better. He has tried a few things. A lot of them have failed,” said Hyers. “We’ve worked on just trying to be shorter and finishing off this last week. It’s just trying to kill some of those habits and not trying to do too much. He’ll feel pretty good in the batter’s box, he’ll feel good in his work, and he gets into the box, he says, and then he just jumps off the back side and creates length.

“It’s just a habit that has gone on and on. I know it seems a player of his caliber [making] those changes should be a lot easier, but to be honest with you, that’s what we’ve been grinding on, is him just to shorten up and not have that length in the back with his hands, to create length and catch up to the fastball. That’s what he’s working on, and obviously to go into the winter trying to improve.”

Pivetta to go Tuesday

Though there’s been no official announcement, recent acquisition Nick Pivetta is expected to make his first start for the Red Sox on Tuesday night against the Orioles.

Pivetta will also get the nod in the season finale at Atlanta on Sept. 27.

Getting two looks at the 27-year-old heading into the offseason should be beneficial for the Red Sox, who got Pivetta and prospect Connor Seabold in the trade with the Phillies for Brandon Workman and Heath Hembree last month.

Pivetta underachieved in his time with the Phillies, but he has enthusiastically been working on refining his pitch mix at the alternate site in Pawtucket, R.I.

Manager Ron Roenicke added that Nathan Eovaldi will make his final start of the season on Wednesday night.

Verdugo, Arroyo banged up

The Red Sox were short-handed for Sunday’s game against the Yankees. Right fielder Alex Verdugo missed his second straight game with a left hamstring injury, and second baseman Christian Arroyo was out with back spasms that forced him out of Saturday’s game in the fifth inning.

“No, they’re not [available Sunday],” said Roenicke. “Hopefully with the off-day tomorrow, being off today, hopefully they’ll be able to go Tuesday.”