The Philadelphia 76ers and Joel Embiid are consulting doctors and considering alternative options, such as surgery, for his injured left knee, sources told ESPN on Sunday.

Both sides have hoped for progress in Embiid's condition, but his determination to play and current treatments -- including regular injections, sources said -- have not led to any improvement.

Embiid is scheduled to undergo tests on his knee early this week, at which point both parties will collaborate with specialists on the best route forward, sources said.

Embiid has publicly and privately said in recent weeks that he might eventually need surgery or an extended rest period for his knee to heal, but he has been determined to find ways to continue playing and be available for the 76ers.

He played just 39 games last season after tearing the meniscus in his knee. He underwent surgery in early February, came back in early April, was part of the 76ers' playoff run and then won a gold medal with the U.S. Olympic team over the summer. He acknowledged earlier this month that he didn't have enough time to fully recover after surgery.

This season, the lingering knee issues, combined with a foot sprain, have caused him to play in just 19 of 56 games.

Embiid is questionable to play Monday against the Chicago Bulls, after experiencing swelling in his knee after Saturday's loss to the Brooklyn Nets, sources said.

He was slow to get up late in the third quarter against the Nets when he lost the ball and hit the court, then was benched late, sitting out the fourth after scoring just 14 points in 31 minutes and missing all six of his 3-point attempts. He has scored 15 or fewer points in consecutive games for the first time since May 2021.

Saturday's loss was significant for the 76ers in a potentially good way; the franchise has broken a tie with the Nets and now has sole possession of the sixth-worst record in the NBA. The 76ers' first-round pick in this draft is top-six protected, otherwise it goes to the Oklahoma City Thunder.

The 76ers, who opened with championship hopes, have lost seven straight games and fallen to 20-36 amid an injury-marred, disappointing season. Even when Embiid, Paul George and Tyrese Maxey all play, Philadelphia is just 7-8.

George also has been dealing with a left pinkie tendon injury and a groin strain, and received injections in order to play in the last four or five games before the All-Star break.

Information from ESPN's Tim Bontemps and The Associated Press was used in this report.