Defense has been Marrero's biggest bugaboo. He started out as a third baseman, but he's blocked there because of Ryan Zimmerman. Marrero then switched to left field, but he didn't have enough range for the spot, so he was moved to first base, where he's expected to be for years to come.
"I'm happy, and I'm going to take advantage of the opportunity that is given to me [in Spring Training]," Marrero said. "I'm going to talk to everybody and listen to what everyone has to say. Everyone has been there. Whatever they say is going to help me."
Since being selected in the first round of the 2006 First-Year Player Draft, Marrero has taken advantage of his opportunities in the batter's box.
In his first full season in professional baseball, Marrero hit a combined .275 with 23 home runs and 88 RBIs for Class A Hagerstown and Class A Potomac. This past season, Marrero got off to a slow start with Potomac, but was on a hot streak when he injured his fibula sliding home on a sacrifice fly against Winston-Salem on June 19.
Marrero didn't think the injury was serious. He got up on his own power and walked to the dugout, not realizing his season was over. Marrero said he could have come back later in the season, but the Nationals didn't want to take any chances on Marrero reinjuring his fibula.
"My cleats just got caught in the dirt," Marrero said. "I didn't think there was anything wrong. I was on the ground for a little bit, but I got up and I was OK. I went to the doctor, and he said there was a little fracture in the bone and I had to take some time off. Usually, when you sprain your ankle, it gets swollen. It was a little red, but it wasn't swollen."
Marrero said the ankle is 100 percent, and he expects to be quicker on the bases after losing a few pounds this offseason.
"I'm trying to come in with more muscle and less fat -- like more in shape," Marrero said. "I'm lifting heavier weights than I have ever did before. I'm running faster now, and I'm hitting the ball harder. I think I lost a little bit more baby fat."