The Celtics have once again received some unfortunate injury news. Shams Charania of The Vertical reported on Tuesday evening that Kyrie Irving will travel to get a second opinion on his sore left knee. 

The Celtics later confirmed that news ahead of their game on Tuesday night against the Oklahoma City Thunder. 

Irving has not played since March 11 against the Pacers, when he played just 16 minutes before leaving due to a sore left knee. The All-Star guard has dealt with knee soreness at various points in the season, and the Celtics did not initially believe the latest issue to be serious. Now, however, it seems things have changed, as Irving's knee has failed to get better. 

Following the Celtics' announcement that Iriving will indeed get a second opinion on his knee, ESPN's Adrian Wojnarowski reported that there is no structural damage to Irving's knee, and the belief is that it will get better with rest. 

That, obviously would be good news for Irving and the Celtics, who have been beset by injuries this season. Gordon Hayward, of course, went down on opening night with a gruesome ankle injury and is unlikely to return. Daniel Theis recently underwent season-ending knee surgery, Marcus Smart had surgery on his thumb that could very well end his season and Jaylen Brown was nearly paralyzed in a frightening fall against the Timberwolves, which he still hasn't returned from.

A few days ago, Celtics GM Danny Ainge went on the radio and said it was possible Irving would need to have surgery on his knee at some point in the near future. However, Ainge said he believed Irving would be healthy for this season's playoffs.