Addressing the media for the first time since it was revealed he is battling post-concussion symptoms, the 24-year-old Staal said those headaches can last up to four or five hours.
"I feel no symptoms if I don't do anything. If I sit on the couch all day I don't get any headache," Staal said. "If I push myself really hard, later in the day, more often than not, I'll get a headache."
Staal is being held out of scrimmages and, at the very least, the team's three North American exhibition games this month. He also took the day off Monday after participating in three days of strenuous physical testing to open training camp.
"Those three days were pretty tough and I came to the rink not feeling all that great, so we decided to take the foot off the gas a little bit," Staal said.
The problems stem from a concussion Staal sustained against Carolina Feb. 22 on a devastating hit delivered by his own brother, Eric, who plays for the Hurricanes.
He sat out three games with a knee injury, also suffered on the hit, and two more in March, presumably for post-concussion symptoms. But it wasn't until the summer that Staal began to notice that he didn't feel right.
"When I first started working out in the summer I couldn't really get through a workout without getting a headache," Staal said. "I had a tough time with that, took some time off, came back and [I've] been steadily improving ever since."
Neither Staal nor Rangers coach John Tortorella seemed willing to guarantee that Staal will be available opening night Oct. 7, when the Rangers kick off the regular season against the Kings in Stockholm, Sweden.
The Thunder Bay, Ontario, native logged a team-leading 25:44 minutes a night for the Rangers last season and finished with seven goals and 22 assists in 77 games.
"As soon as I get a stretch in where I'm not getting headaches after workouts or have a day like [Monday] after three hard days, I'll start playing games," Staal said. "Hopefully, that's sooner rather than later."
Staal said he won't seek out additional specialists or opinions unless he regresses. Until then, the team's medical staff will continue to treat his condition with precaution.
"With all the attention it's been getting it's kind of a tricky area to predict or to say what to do," Staal said. "Right now I'm improving with working out and working hard so we're going to keep going in that direction until something changes."
As for his brother Eric?
"He's not real happy about it, no," Staal said. "But it is what it is. You can't do anything about it now."
Katie Strang covers the NHL for ESPNNewYork.com.