WASHINGTON, D.C. -- The Nationals were virtually injury free during Spring Training. The only serious one came from right-hander Jason Simontacchi, who strained his right groin and is expected to be back with the Major League squad by the end of April.

However, the Nationals were hit with two potentially devastating blows Opening Day. Center fielder Nook Logan suffered a hyperextended left foot, while shortstop Cristian Guzman suffered a mild left hamstring strain. Both players are listed as day to day.

"We were pretty much healthy in Florida, and then two guys go down," manager Manny Acta said.

Logan's foot injury occurred in the top of the fourth inning. With one out in the top of the fourth inning, Marlins second baseman Dan Uggla hit a deep fly ball to straight away center field. Logan was able to get a bead on it and caught the ball, but his foot was stuck under the wall. Logan then started hobbling and sat on the ground. Right fielder Austin Kearns, Acta and trainer Lee Kuntz then came to Logan's aid.

"At first, I didn't know how bad it was," said left fielder Ryan Church. "As soon as he threw the ball in, you could see the expression on his face. Then I knew exactly what he did."

Kuntz wanted to bring a cart on the field, but Logan refused. A few minutes later, Logan was able get up, but Kuntz had to help Logan off the field. Initial X-rays were negative. Later in the day, Logan had an MRI, but would not say what the prognosis was. The team is expected to make an announcement on Tuesday

"It's very sore. I'm wearing a boot. I don't know [if I'm going on the disabled list]," Logan said on the telephone.

If Logan goes on the disabled list, there is an excellent chance that Kory Casto will be called up. The team was impressed with the way Casto was patient at the plate and could play left field, right field, third and first base very well.

Casto was the last cut of Spring Training because Church and outfielder Chris Snelling were out of options. The only way Casto would have made the roster was if Logan started the season on the disabled list. On March 24, Logan suffered a strained right groin and was expected to be out two weeks, but he was back on the field in five days.

When reached by phone, Casto said the team had not promoted him to the big leagues and he heard about Logan's recent injury through a reporter.

"I didn't see the game, and no one has called me," Casto said.

Whether Casto becomes an everyday player remains to be seen, but Church will move to center field if Logan is not ready.

"I'm going to come in here expecting to be in the lineup. I don't care where I play," Church said.

The Guzman injury appears to be a lot worse, according to Acta. On a 1-0 pitch in the bottom of the fifth inning, Guzman hit a ground ball to third baseman Miguel Cabrera. Guzman was seen limping toward first base. Guzman jogged to first base and received a round of boos from the fans, who didn't realize Guzman was seriously hurt. Guzman had an MRI and will be re-evaluated Tuesday.

"Cristian is probably more serious than Logan. We have to take in consideration that a hammy doesn't heal overnight," Acta said.

The skipper said if Guzman is out for an extended period of time, second baseman Felipe Lopez will move over to short and Ronnie Belliard will be the second baseman. However, Lopez sounded like a man who didn't want to make the switch.

"I don't want to start all over again," Lopez said. "My mind is set for second base. It's not hard to make the switch [to shortstop]. I've already got my mind set. I've got my game plan. It's not hard, but I'm comfortable now."