The news comes a few hours after Johnson saw Dr. Brian Kelly, a hip specialist in New York City.
"We are going to do some more studies. We are going to do a nerve study and now we are going to do an MRI and look some more," general manager Jim Bowden said.
Johnson has not played a Major League game since last Sept. 23, when he broke his right leg in a collision with right fielder Austin Kearns against the Mets at Shea Stadium. While the bone in the leg has healed, Johnson continues to have problems with the hip.
Johnson has been taking batting practice, fielding ground balls and running the bases, but he has been limited in what he can do. When he is fielding ground balls, for example, Johnson can't go to his left very well. He also limps whenever he tries to stop at a base. According to Bowden, Johnson has problems hitting certain pitches in the zone.
Johnson indicated that his hip has been sore for several weeks. Asked if he felt that the sore hip is a setback, Johnson hesitated and said, "No. I just don't want it to keep lingering on. I want to find out why pain is still there. I never had something like this before."
Johnson sounded like a man who wasn't sure he would play a game this season.
"I want to. I'll keep working. That's my goal. I have to be healthy before I go out there. I have to keep pushing forward," he said.
Trade rumors: According to a baseball source, the Nationals are surprised that American League teams have not rushed to acquire Dmitri Young's services. But they believe that the interest will be there for him close to the July 31 trade deadline.
Thus far, according to the source, only the Braves have shown interest. The news about Atlanta was first reported on FOXSports.com. The Braves are reportedly not happy with their first-base platoon of Scott Thorman and Jarrod Saltalamacchia. There is a feeling if Young went to the Braves, Young would platoon with Saltalamacchia, who is hitting .314. Thorman is hitting .223 with nine home runs and 33 RBIs.
Young, who will be the Nationals' All-Star representative Tuesday in San Francisco, is the hottest hitter on the team. He entered Friday hitting .339 with eight home runs and 42 RBIs.
A sighting: Shortstop Cristian Guzman was spotted in the Nationals' clubhouse Friday. He said he had a softer cast put on his left thumb, which he hurt against the Indians on June 24. Guzman, who is out for the season, said he spends most of his free time watching TV and Nationals games.
"I feel bad because I want to be here every day with my teammates -- just play and have some fun here. Now I have to be at my house all day. But I'll be all right," Guzman said.
Guzman was hitting .329 with two home runs, 14 RBIs and an on-base percentage of .382 at the time of the injury.
Stat of the day: The Nationals are 8-37 when their opponents score first this season.
Did you know? Entering Friday's action, Young is hitting a Major League-leading .415 in his last 44 games.
Coming up: The Nationals play the second game of a three-game series against the Brewers on Saturday night at Robert F. Kennedy Stadium. Washington right-hander Jason Simontacchi (5-6, 6.27 ERA) will face Milwaukee right-hander Jeff Suppan (8-7, 4.90 ERA).
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.