Jayson Werth. (Alex Brandon/Associated Press)

The streaking Washington Nationals were dealt a blow Thursday when a CT scan, essentially a higher-quality exam, of Jayson Werth’s ailing left wrist revealed two small fractures, according to a person familiar with the situation. Werth’s wrist, which hasn’t improved enough since it was hit by a pitch May 15, will be immobilized for four weeks. The hope is that the 36-year-old veteran left fielder, after rehabilitation, could be back with the Nationals as soon as August.

Werth was examined Thursday by Richard Berger, a wrist specialist, of the Mayo Clinic in Rochester, Minn. Over the years, Berger has treated Werth’s left wrist, which has been a magnet for pitches and frustrating injuries, including one that threatened his career earlier.

The Nationals have risen to the top of the National League East thanks to a 21-6 run over the past month but with limited contributions from Werth, one of the team’s leaders. The Nationals are third-highest scoring offense (4.66 runs per game entering Thursday’s game) in the major leagues. Werth spent spring training working his way back from offseason surgery on his right shoulder, a procedure that kept him out until mid-April. He hit .208 with two home runs in 27 games after returning, but he was improving of late; he was 5 for 17 with a home run and four RBI in the five games before his injury.

The Nationals will have to continue filling left field and the lack of Werth’s production for, at least, the next two months. The team hasn’t made any official announcements about Werth’s results. The injury was first reported by MLB.com’s Nationals site.

Berger has played an integral part in nursing Werth’s left wrist back into shape. After Werth was first hit in the left wrist by a pitch in 2005, tore a ligament, dealt with months of pain, missed a year and had a surgery that didn’t solve the problem, Berger diagnosed the trouble and performed surgery to fix it in 2006. Berger inserted screws and a plate into Werth’s wrist when he broke it in 2012 diving for a ball in right field. After discomfort persisted in Werth’s wrist following his hit-by-pitch earlier this month, he went to see Berger.

Two weeks ago, the initial x-ray in San Diego the night Werth was hit by a a 92 mph fastball from Padres starter Odrisamer Despaigne came back negative. (Imagine how much worse Werth’s injury could have been if he hadn’t been wearing a wrist guard.) A MRI exam four days later in Washington with the Nationals medical staff showed no broken bones or ligament tears. But Werth continued to experience swelling and soreness, which prevented him from rotating the wrist and swinging a bat.

“I wish it felt better,” Werth said on May 19. “I’m optimistic but I don’t feel like I’m out of the woods yet. Hopefully in a couple days it’ll respond a lot better and we can get going. Right now, it’s still pretty banged up. So the tests were good but I still feel like we’ve got a ways to go … As bad as it could be without being broke.”

Nationals General Manager Mike Rizzo said Wednesday that Werth’s range of motion had improved in recent days and the visit to Berger was planned for Thursday’s off-day as a chance for the outfielder to visit his “safety blanket.” The visit, however, brought tough news for the Nationals and Werth.

It is unclear how the Nationals will fill left field for the next two months but they have options. Perhaps the soundest is to play 24-year-old Michael A. Taylor there every day. Taylor, the Nationals’ top outfield prospect entering the season, is 2 for his last 25 with 12 strikeouts. He could benefit from regular playing time. But his inexperience and struggles at the plate have led to a platoon over the past two weeks with Tyler Moore and Clint Robinson.

Moore (.721 on-base-plus-slugging percentage) is right-handed and Robinson (.593 OPS) is left-handed but neither are natural outfielders. Veteran outfielder Nate McLouth, on the disabled list all season, is progressing but still rehabbing from setbacks following right shoulder surgery late last summer. Left-handed-hitting outfielder Matt den Dekker, acquired in the late spring Jerry Blevins trade, is hitting .228/.295/.287 with one home run at Class AAA Syracuse, although he has improved of late; he is 15 for his last 52.

The Nationals could always look outside the organization for immediate outfield help and depth. Ideally, Taylor, pegged as the Nationals’ outfielder of the future, would seize a hold of the outfield void for now as he did earlier in the season during Denard Span’s absence. Nationals left fielders rank 25th out of 30 teams with a .588 OPS so far.