Anthony Rendon. (Photo by Jonathan Newton / The Washington Post)

Updated, 9:23 p.m.: JUPITER, Fla. – Nationals third baseman Anthony Rendon is getting a second opinion on his balky left knee. Rendon was slated to visit orthopedic surgeon  James Andrews on Monday.

“We’ll see what the doc says and that it from there,” General Manager Mike Rizzo said on Monday afternoon after the Nationals’ spring training game against the Cardinals. “… We give a second opinion to just about every player that is seen by our team doctor.”

In fact, the plan as of Monday for Rendon is to have his left knee also evaluated by a third doctor, according to people familiar with the situation. Rendon is also scheduled to visit with a knee specialist from the Steadman Clinic in Vail, CO. Rendon’s knee has bugged him longer than first expected and this way his joint can be examined by several sets of expert eyes to be sure why.

Rendon, a cornerstone of the Nationals’ infield who finished fifth in National League MVP voting last season, has not played since March 9. He has rested and received treatment, but his knee has remained sore, especially when he tries to move laterally.

After Rendon initially hurt his knee making a diving stop at third base, Manager Matt Williams said he needed a day to rest. Rendon was later diagnosed with an MCL sprain, but Williams said the third baseman would be shut down for a few days. Three weeks later, Rendon has still not resumed baseball activities.

Surgery is not often needed for MCL sprains, essentially the stretching or tearing of the ligament, but only when the MCL is only part of the knee that has been affected, according to the National Institutes of Health. Rest and treatment are the most common treatments for MCL sprains.