Dwyane Wade missed his fourth game in a row Thursday because of soreness in his knee. Wade was ruled out Thursday morning after the Heat’s shootaround at AmericanAirlines Arena. Wade has missed 13 games this season as he recovers from offseason shockwave knee therapy.

The OssaTron treatment Wade received in the offseason summer is expected to strengthen his knees and help to extend his career, but the full recovery time following the procedure is about six months. Teammate Rashard Lewis underwent the procedure last year.

Wade last played Jan. 17 against the 76ers and afterward scratched himself from the active roster for the next night’s game against the Bobcats. He hasn’t played since. Wade scored eight points in each of his past two games.

It has been a trying week for Wade, who addressed his health on Twitter on Wednesday, an off day for the Heat.

“Thanks to every[one] who has been concerned about my health this year,” Wade wrote. “It’s mentally challenging to say the least. ... But you don’t get results by being mentally defeated. I’m in the lab trying to get better everyday for my team.”

Wade then posted a hashtag of “my belief is stronger than doubt.”

On Thursday morning, Heat coach Erik Spoelstra said Wade’s absence from the lineup isn’t cause for concern, but this is the longest stretch of inactivity for Wade this season. He sat out two games in a row twice before.