Brooklyn Nets star Kyrie Irving suffered a nasty ankle sprain in Game 4 against the Milwaukee Bucks on Sunday, and Los Angeles Lakers star LeBron James took to Twitter with his dismay at seeing his former teammate go down.

LeBron's tweet was blunt:

Irving suffered the ankle injury when he landed on Giannis Antetokounmpo's foot. He went down in pain right away and stayed on the court for a while before limping to the locker room. He was ruled out for the remainder of Game 4 during halftime.

The Nets were already without James Harden, so losing Kyrie Irving is a brutal blow against a Bucks team that suddenly seems to have a lot of momentum. It looked like Brooklyn was going to cruise to a series victory after dominating the first two games, but Milwaukee has turned the tables and now has a legitimate chance to advance to the Eastern Conference Finals.

The Nets are no stranger to dealing with injuries to their stars this season. Their Big Three played just eight regular-season games together and then the five first-round games before Harden got hurt early in Game 1 against Milwaukee. Brooklyn will have to dig deep with Harden and Irving hurting, with the lone healthy star left in Kevin Durant needing to step up and get help from the role players.

LeBron James knows just how special Kyrie is after they played together for the Cleveland Cavaliers. They went to four consecutive NBA Finals against the Golden State Warriors and won in 2016, erasing a 3-1 deficit in the process. LeBron and Kyrie put together some historic performances in that series to beat the 73-win Warriors, and they both had iconic moments in Game 7. Irving hit the game-winning shot over Stephen Curry, while LeBron had that incredible chase-down block of Andre Iguodala.

Let's hope Kyrie Irving doesn't miss much time.