Nationals second baseman Daniel Murphy underwent microfracture surgery on his right knee last October and has been rehabbing ever since. That will continue to be the case once the MLB season gets underway next week. 

Murphy, entering his age-33 season, hasn't appeared in any spring training games, so him not being ready for Opening Day was expected to be the case. It's what came with the news that is a bit jarring. 

In relaying Murphy admitting he won't be ready to start the season, the Washington Post reports that Murphy has been unable to run on the field or take any at-bats. He's only been running on a treadmill and taking grounders hit right at him (no lateral movement). 

Manager Dave Martinez even mentioned in the report that the club doesn't want him back in the majors until he's 100 percent. 

It makes perfect sense. Having Murphy push himself to get back ASAP and then seeing his knee swell up and force him back on the shelf would be stupid and cause him to miss even more time than initially expected. 

Still, let's be realistic here. The season starts in a week and a day. Once Murphy is 100 percent, he'll need to work himself into game shape and get his timing back at the plate. Then he'll need a minor-league rehab assignment. Even the most optimistic estimates would have to peg a late April or even early May return to the Nationals for Murphy, right? 

Given his age, it's entirely possible that Murphy could miss something like two months. 

Murphy hit .322/.384/.543 with 43 doubles, 23 homers, 93 RBI and 94 runs last season. He's been an integral part in a potent lineup in his two years with the Nationals. 

Without Murphy, Howie Kendrick and Wilmer Difo figure to get the playing time at second base.