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05/17/2013 4:04 AM ET

Johnson hopes to get more from Espinosa on offense

SAN DIEGO -- Manager Davey Johnson decided not to start second baseman Danny Espinosa in Thursday's game against the Padres.

Espinosa is 22-for-124 (.177) to start the season, and Johnson had a talk with Espinosa before the game and hopes to have more conversations with Espinosa in the future. Johnson didn't go into details on what was said, but it was obvious he wants Espinosa to improve his hitting.

Johnson still believes in Espinosa and called him a driven ballplayer, who is trying to do too much at the plate.

"When you start to do too much, sometimes you get into some bad habits, mechanics can go a little bad," Johnson said. "It was a good conversation. I hope it opens up to more conversations.

"I know a little something about hitting. I know how hard it was when we had a tendency to try more things than we should be trying. I think in [Espinosa's] case and his will to really do well and help this team, he has been trying to do too much. Hopefully, he can relax work on some things and he'll be fine."

Johnson started Steve Lombardozzi at second base, and he went 1-for-4 with a run scored and an RBI in a 6-2 victory over the Padres.

After inconclusive MRI, Detwiler to receive another

SAN DIEGO -- Nationals left-hander Ross Detwiler arrived at Petco Park early Thursday afternoon and was informed that he had to go to the doctor and get an MRI on his lower back, which he hurt Wednesday night against the Dodgers. According to manager Davey Johnson, Detwiler wasn't happy that he had to go 30 minutes away from the park to get the back checked.

The MRI on his Detwiler's back turned out to be inconclusive. Detwiler is going to get another MRI before the week is over.

"It's going to be a broader MRI than this narrow one," general manager Mike Rizzo said after the team's 6-2 victory over the Padres.

Johnson is not sure if Detwiler will make his next scheduled start against the Giants on Monday. Johnson didn't rule out having a bullpen by committee throw that day. Relievers Zach Duke or Craig Stammen could start the game. It would make sense if Stammen received the start because he pitched Wednesday, the same day that Detwiler pitched. If Detwiler misses one start, there isn't a need to put him on the disabled list.

"We think he is going to be all right," Johnson said. "He was a little stiff and sore this morning, but he is going to be all right."

Detwiler sustained tightness in his lower back in the top the third inning on a sacrifice bunt that advanced Roger Bernadina to second base. Detwiler had problems running the bases. His back got worse in the bottom of the inning.

It was believed that he hurt his back while catching a wide throw from shortstop Ian Desmond in the bottom of the third, but Detwiler said he felt fine.

Detwiler had problems throwing pitches after that, and pitching coach Steve McCatty, head athletic trainer Lee Kuntz and Johnson came to his aid. Detwiler stayed in and allowed a single to A.J. Ellis and walked Andre Ethier to load the bases. He got out of the inning when Scott Van Slyke lined out to third baseman Ryan Zimmerman. The left-hander was then replaced by Stammen

Harper homers in return to starting lineup

SAN DIEGO -- On Thursday, Nationals outfielder Bryce Harper started his first game since Monday night and showed no ill effects after crashing into the right-field wall at Dodger Stadium.

Harper went 1-for-4 in a 6-2 victory over Padres and hit his 11th home run of the season. With two outs in the seventh inning, Harper swung at the first pitch from right-hander Tyson Ross and hit a monster home run over the center-field wall to increase the Nationals' lead to four.

The ball was hit an estimated 431 feet, the second longest hit at Petco Park, according to ESPN's home run tracker.

"The Padres pitched him tough. He hit a heck of a pitch -- a great sinker and he crushed it. It's nice to have him back," manager Davey Johnson said.

Nats place Ramos on 15-day DL with hamstring injury

SAN DIEGO -- The Nationals placed catcher Wilson Ramos on the 15-day disabled list with a left hamstring strain and recalled catcher Jhonatan Solano from Triple-A Syracuse.

Ramos re-injured the hamstring Wednesday night against the Dodgers after he singled in the fourth inning. The hamstring started to bark at him two innings earlier after he doubled off Dodgers right-hander Zack Grienke. Manager Davey Johnson wished Ramos had come forward and said something that inning.

Ramos will now go back to Washington this weekend to be re-examined by the team's doctor, Wiemi Douoguih. Ramos is expected to get an MRI. It marked the second time this season Ramos had to go on the disabled list because of the left hamstring strain. Ramos said the hamstring was sore on Thursday.

The young catcher is mystified as to why he is having hamstring problems this season. He thinks it's because of his right knee, which was surgically repaired last year, resulting in him putting "more pressure" on the left leg.

"I was working a lot on my hamstrings. I wanted to make it stronger," Ramos said. "I was feeling very good yesterday before the game. I don't know."

Solano, who is 1-for-6 in three games with Washington in 2013, was recently activated from the 7-day disabled list on Tuesday. He missed time because of a right ankle sprain, which he hurt trying to break up a double play at home plate.

Solano was able to play in a Minor League game on Wednesday for Triple-A Syracuse. He played all nine innings and said the ankle didn't give him any problems.

"I'm happy to come back," Solano said. "I want to help the team win. … I will have my chance to play."

Werth misses rehab game with tight hamstring

SAN DIEGO -- Right fielder Jayson Werth was scheduled to play for Class A Potomac on Thursday, but he went to see his doctor in New York because he felt tightness in his right hamstring.

However, Werth is expected to get a rehab start for Potomac on Friday and stay with the team a few more days, which means he will not be activated from the disabled list on Saturday. Werth will likely re-join the Nationals sometime next week when they play the Giants in San Francisco.

"I want to see where he is at, when he can play some games," general manager Mike Rizzo said. "I think it's safe to say he is going to be pushed back a couple of days."

Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.