The Boston Celtics’ latest injury report for Friday night’s showdown with the first-place Cleveland Cavaliers at TD Garden includes several players, but one in particular stands out.

Veteran guard Jrue Holiday has been ruled out with a “mallet finger” injury on his shooting hand. It’s unknown if this injury will result in Holiday missing an extended amount of time, but it doesn’t sound like a pleasant ailment.

What is mallet finger? Here is the Cleveland Clinic’s definition:

“Mallet finger is an injury to the tip of your finger that causes it to droop downward, making your finger look like a mallet. It happens when you injure the extensor tendon that extends the tip of your finger (terminal extensor). If this tendon gets torn, cut or displaced, it won’t be able to pull your finger joint straight.

“Mallet finger is a common sports injury, especially among baseball players. (Its other name is baseball finger.) It can happen when something hard hits your extended fingertip, like a flying ball that you’re trying to catch. You may also get it by accidentally striking your fingertip or getting it caught in a door.”

Here’s another explanation from NBA injury analyst Jeff Stotts of In Street Clothes:

“Mallet finger is an injury to the tendon that helps straighten the DIP joint (finger tip). Players have played with the injury while others have needed surgery. It often depends on the severity of tendon damage (and) the involved digit.”

Before Friday’s game, C’s coach Joe Mazzulla said Holiday is “day-to-day, just managing the pain.”

Oklahoma City Thunder forward Lu Dort played through a mallet finger injury earlier this season. He wore a splint on the injured finger, and it sounds like the injury definitely impacted him.

“It was just hard for me to shoot,” Dort told Joel Lorenzi of The Oklahoman for a story published Dec. 5. “That was the main thing. I felt like I got off to a great start on that side of the floor. And it was just hard for me to shoot the ball with four fingers, basically.”

The Celtics haven’t said when the injury occured, but it wouldn’t be surprising if it was bothering Holiday in Wednesday’s loss to the Detroit Pistons. Holiday shot 2-for-10 (0-for-5 from 3-point range) in 31 minutes as the Celtics lost 117-97.

Holiday has played in 47 of Boston’s 59 games so far this season. The 34-year-old guard is averaging 10.8 points, 4.3 rebounds and 3.7 assists per game, while shooting 34.2 percent from 3-point range (his lowest percentage since 2018-19).

This injury comes at a time when the Celtics have some tough games on their schedule. The C’s play the Cavaliers, Denver Nuggets, Los Angeles Lakers and Thunder over the next 12 days.

Jrue Holiday is one of the most valuable players on any team he plays for, and his presence on the Boston Celtics is no exception. As one of the league’s best perimeter defenders, he takes on the toughest matchups every night, shutting down elite scorers and disrupting offensive game plans. His ability to guard multiple positions while also being an efficient playmaker makes him a crucial two-way asset. Beyond defense, Holiday brings championship experience and leadership, something the Celtics need as they push for an NBA title. Without him, Boston loses a key piece of its defensive identity and floor balance.

Offensively, Holiday may not always be the first scoring option, but his playmaking and ability to hit clutch shots make him a game-changer. He provides much-needed stability in the backcourt, allowing stars like Jayson Tatum and Jaylen Brown to focus on scoring while he handles ball distribution. His ability to step up in big moments, as seen throughout his career, is why he’s such a vital part of any championship-contending team. If he’s sidelined for too long, the Celtics will struggle to replace his defensive intensity and veteran presence, which could impact their chances in a deep playoff run.