The hits keep coming for the Chicago Bulls. Just days after point guard Derrick Rose underwent a meniscectomy to remove a tear in his medial meniscus, All-Star guard Jimmy Butler suffered a significant elbow injury in a loss to the Clippers.

The injury occurred when Butler collided with Clippers center DeAndre Jordan. The impact placed a significant type of force known as valgus stress onto the elbow joint, overloading the ulnar collateral ligament (UCL) on the inside portion of the elbow. According to the team’s official site, a subsequent MRI revealed a “Grade 2/3 ulnar ligament sprain and small bone impaction injury to the left elbow.”

The UCL is quite notorious in sports medicine as it is the ligament that is repaired in Tommy John surgery, a procedure that is becoming commonplace in Major League Baseball. During last week’s MIT Sloan Sports Analytics Conference, Dr. Glenn Fleisig revealed that 25 percent of current MLB pitchers have undergone Tommy John. Recovery following Tommy John is a lengthy and arduous process for pitchers but this is largely in part to the high amounts of stress they put on and through their elbows when they deliver an overhand pitch. Since this motion is uncommon in basketball, the injury and the surgery are considered unusual in the NBA.

However there are several examples to examine. Since the 2005-06 season, there have been six reported cases of UCL sprains in the NBA. Each of the five involved players avoided surgery including New York Knicks forward Andrea Bargnani, who sprained his right UCL in 2012 and his left UCL the following season.

While the sample size is small, the average number of missed games for these cases is a UCL sprain in the NBA is 23 games, though the number drops to 15 games when complete tears are excluded. Butler’s injury has been graded somewhere between a Grade 2 (partial tear) and a Grade 3 (complete tear). If Butler were to in fact miss 15 games, he would return in the 76th game of the regular season on April 3 against the Pistons and in line with the four-to-six week window the Bulls are currently expecting. He could very well return sooner but his recovery will also have to factor in the impaction injury. This description is used when the outer layer of a bone is damaged and is often referred to as a bone contusion. The body’s natural healing response treats these impaction injuries just as it would a fracture, with new bone tissue being formed to fill in the cracks to the outer layer.

Both Rose and Butler appear to be on a similar timeline. If all goes well during the rehab process both injured All-Stars could be back before the conclusion of the regular season with a chance to get a few games in before the postseason. Until then the team will have to hold off a suddenly surging Cleveland team with a makeshift backcourt of Kirk Hinrich, Tony Snell, and Aaron Brooks.