Viera, FL (SportsNetwork.com) - Washington Nationals center fielder Denard Span will likely miss the start of the season after undergoing surgery on Monday for a core muscle problem.

Span had surgery for a sports hernia in early December, but began feeling pain in his right core muscle a few weeks later. It worsened after playing in a spring training game last week.

"Everything went well with the surgery," Span wrote Monday on Twitter.

Nationals manager Matt Williams said Span is expected to rejoin the team later this week to begin the rehab process, which should take between 4-to-6 weeks.

Span is coming off a strong 2014 season, his second with Washington after spending his first five major league campaigns with Minnesota. The 31-year-old veteran hit a team-best .302 and added an NL-best 184 hits with a career-best 31 stolen bases.

Washington exercised its club option on Span for the 2015 season last October.

A career .286 hitter, Span has amassed 32 home runs, 314 RBI, 141 steals and 55 triples over 889 major league games.