WEST PALM BEACH, Fla. -- Washington Nationals second baseman Daniel Murphy, who is recovering from microfracture surgery on his right knee, doesn't think he'll be ready for Opening Day.

"It's reasonable to expect I won't be in the Opening Day lineup," Murphy said Wednesday.

Murphy, whose .322 batting average ranked second in the NL last season and fourth in the majors. had the procedure in mid-October and started taking live batting practice a week and a half ago. Over the past few days, he has been incorporating lateral movement in his ground ball work.

He hasn't seen any game action and said he was hoping for a faster rehab process.

"I think naturally for any athlete, I'm going to come back later than I wanted to," Murphy said. "Due to the fact that this is the first time I've had microfracture surgery, I wasn't really certain what to expect. I'd talked to other guys who had gone through it, but each individual surgery or injury is unique. So I think whenever I do come back, from my personal perspective, it will be later, but it doesn't mean it'll be wrong."

Although Murphy has yet to be officially ruled out for Opening Day, manager Davey Martinez is prepared for it.

"We have guys that can step in," said Martinez, who would likely use Wilmer Difo or Howie Kendrick in Murphy's absence. "We're going to miss him for sure, but with those guys in the lineup, we're going to be fine."

Washington, which won its second straight NL East title last season before losing to the Cubs in the National League Division Series, opens the season at Cincinnati on March 29.