Bryce Harper hyperextends knee, MRI Sunday (Nats win 3-1)

Following a three-hour rain delay, the Nationals lost right fielder Bryce Harper to a left knee injury when he slipped on first base as he tried to beat out a grounder in the first inning.

Harper could not put weight on his left leg and was helped off the field by trainer Paul Lessard and Nationals hitting coach Rick Schu.

The Nationals defeated the Giants 3-1, but the concern now is the status of their 2015 National League MVP for the rest of the season.

Manager Dusty Baker said Harper suffered a hyperextended left knee and will undergo an MRI Sunday morning.

With one out and Wilmer Difo on second in the bottom of the first, Harper sent a grounder towards Giants first baseman Ryder Jones. Jones and Harper raced to first base and Jones got there first for the out.

"It was one of those plays where I went to flip and (Jeff "Shark" Samardzija) wasn't there," Jones recalled. "I think he thought maybe he could beat it out for a knock. I think Shark said he tried to extend the knee a little bit and try to catch the corner of the bag, and I think he might've slipped on the top. It was a little wet, it didn't look good. I hope he's alright. It's just one of those freak plays where you kind of thought there would be a collision and there wasn't and that might be part of it too, maybe he was trying to dodge me and Samardzija.

"The top of the bases were wet obviously from the rain. It looked like we were about to collide because Samardzija was kind of right there too. Just a freak accident. I guess we'll find out what happened to him, but it didn't sound too good. He looked like he was in pretty good pain. You never want that to happen to a player. Hopefully he's alright."

Nationals first baseman Ryan Zimmerman, who smacked an RBI double in the at-bat after Harper was helped off the field, feels for his fallen teammate and was reminded of the injury to Adam Eaton at first base in April. Eaton is recovering from a torn ACL and other leg damage. "Obviously you don't want anyone on your team to get hurt," Zimmerman said. "He's a big part of the team. Any time something like that happens after already going through something like that earlier in the year, it's not good to see that."

Manager Dusty Baker, like Zimmerman, thought about a late season injury to one of his players that was similar to the way Harper hit the ground. He hopes it's not the same injury that felled catcher Wilson Ramos at home plate last season.

"My first thought was to think about Ramos last year down the stretch," Baker said. "So I'm hoping that's not the case.

"We just ask for prayers that it's not serious. We're just urging everybody out there that are Nationals fans and baseball fans to say a prayer for him tonight because he was in obvious pain out there. We're just hoping for the best."

With the rain making the grounds wet, and the fact that it appeared Harper slipped on a wet first base bag as he stretched for the play, did Baker think they shouldn't have started the game with the field still saturated by a three-hour rain?

"No, no. It was in the hands of the league, really," Baker said. "The unbalanced schedule here, this is their last trip in. You had to try to play the game. This is their only time in with the unbalanced schedule, so we were kind of at the mercy of the schedule."

Baker described what he saw when he approached Harper.

"He was in obvious pain, and he was praying and I was praying, too," Baker said. "He was talking to the Master. That's what we usually do when things are in a bad way. The good thing is he's young and strong. I'm very optimistic that he'll be at least fine shortly."

After the game, starter Edwin Jackson was optimistic that maybe the Harper knee injury wasn't as serious as some might have thought when they initially saw the injury occur.

Harper was seen leaving the clubhouse with just a slight limp. Jackson (3-2), who pitched six innings and allowed just one run on five hits to pick up the win, said it was nice to see Harper moving around in the clubhouse after the injury.

"When you see a caliber of player like that or any player go down like that, you hope for the best," Jackson said. "And fortunate that he's up and walking. He's definitely one of those guys that you can't replace on a team.

"It's crazy, but it's definitely great to see him up in spirit and walking around and know that he won't be significantly out for a period of time, or just hurt period. He's doing great."