Morneau, who has missed just five games this season despite the injury, received two cortisone shots in his neck and met with doctors, who told him the pain is unlikely to go away.
But Morneau was able to put that aside on Tuesday, homering twice and scoring three runs in the Twins' 8-7 loss to the Tigers.
"He was driving the ball and put it in the seats a couple times," Twins manager Ron Gardenhire said. "We need that, especially with [Jason] Kubel out. We need somebody to pick up the slack and he did that tonight."
Before the game, Morneau told reporters about his ailment and how it's something he's likely to play through this season.
"We got it checked it out, and there's not really a whole lot that can be done," said Morneau, who added that he's never dealt with this injury before this year. "We shot it twice, and it feels better today than it did a while ago. So the hope is that it'll continue to get better.
"It's not something they really want to do surgery on. They say typically the time to recover is about the same amount of time to recover from the surgery. So it's one of those things where it's playable, and as long as the pain is tolerable, we'll keep grinding it out. So that's kind of where we're at."
Gardenhire met with Morneau last week to see if a trip to the 15-day disabled list would help, but after Morneau met both with team doctors and his own personal doctor, they decided it wouldn't make a difference.
"Do you want to let it try to calm down for a couple weeks if it's just going to come back? Or do you work through it?" Gardenhire said. "That's kind of where we're at. I asked him that question, too, 'If it's the right thing for you to do, sit out for a couple weeks, back off and let this thing calm down, we'll do that.' I try to protect him as much as I can, but no one really thinks that's going to help much."
Morneau said he feels the malady both at the plate and in the field, but it's mostly hindered his ability to lift weights, as it's affected the strength in his left arm. He added that if the injury lasts into the offseason, they could explore other options, including surgery.
Morneau refused to blame the injury for this struggles this season, though. He's batting .247, with a .299 on-base percentage and .371 slugging percentage in 48 games with four homers, but he said it's affected him defensively with his range of motion and reaction time.
"Right now, it's playable, and I'm able to go out there," Morneau said. "Obviously, I'm not playing as well as I'd like, but whether it's because of this or not, who knows? It's one of those things, where I can play with it so I'll just keep going."