According to general manager Jim Bowden, Hill said the forearm felt much better after receiving the shot, however, there's no telling when Hill will throw again.
Hill played catch on Friday, but he had to stop after a few minutes because his forearm was in serious pain. Hill has yet to play in an exhibition game because of the injury.
Hill has been experiencing tightness in the forearm for more than a month, but managed to throw in bullpen and batting practice sessions. In his last batting practice session last week, Hill was in a lot of pain.
Hill received a second opinion on his sore right forearm on Tuesday at Duke Medical Center, and the results were positive.
The Nationals are mystified as to why Hill is still in pain because the radial nerve in his forearm is normal and does not require surgery. The team is considering another opinion.
"We don't know why he has pain there. We haven't had a doctor or anyone tell us exactly what it is," Bowden said. "Maybe the cortisone shot will get him over the hump. We are going to keep trying to find a solution."
Hill was eating peanut butter and jelly sandwiches and acted as if everything was normal with the forearm.
"I had to cut it off," Hill said. "I wasn't feeling 100 percent. I wasn't happy with it. It wasn't all that bad. It was kind of the same. We were hoping for improvement. Whatever program they have for me, I'm still on it."
Asked if he had any concerns about the arm, Hill said, "No. We are trying to calm it down and make it go away. There is nothing structurally wrong. It's just a matter of getting through it. At this point, it's still the same program.
Manager Manny Acta is holding out hope that Hill will be on the Opening Day roster. Since he is behind the rest of the teammates on the staff, Hill most likely would start the season as a fifth starter and probably would not start a game until the series against the Cardinals.
"I'm anticipating him being OK, unless he is unable to pitch through the pain, which is probably what he has to do," Acta said.
During his eight years in professional baseball, Hill hasn't been able to escape injury. When he was drafted in the sixth round of the 2000 First-Year Player Draft, Hill already had a sore right elbow.
By the 2004 season, he needed elbow reconstruction surgery and it took him almost two years to recover. Hill returned to the big leagues in 2006, but he didn't pitch until after June 28 because of elbow soreness. Scar tissue was causing problems in the elbow.
Last April, after getting off to a good start, Hill hurt his left shoulder running the bases against the Marlins. He pitched through the injury, but he changed his mechanics and it ended up hurting his forearm. As a result, Hill missed the last three months of the season.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.