Dallas Mavericks power forward Kristaps Porzingis recently had a platelet-rich-plasma injection as part of the treatment for the soreness in his right knee that has sidelined him since New Year's Eve, sources told ESPN.

The Mavs commonly use PRP injections to stimulate or assist healing and address symptoms such as pain in a variety of injuries, a source said, adding that the team occasionally uses it as part of preventative maintenance. The injections use elements of the patient's own blood, not medicine.

Sources said the injection is not a factor in Porzingis' continued absence, but the soreness in his right knee has not subsided enough for him to be cleared to play. An illness this week has delayed Porzingis' recovery, preventing him from going through the quality workouts that are a critical part of the process.

The Mavs are committed to taking a cautious approach with the 7-foot-3 Porzingis, who was recovering from a torn ACL in his left knee when Dallas acquired him from the New York Knicks in a blockbuster trade last season. The Mavs originally planned for Porzingis to sit out one game of back-to-backs in the early part of the season, but he rested only one game in total before being sidelined by the right knee soreness.

Porzingis was a late scratch before the Mavs' Dec. 31 road loss to the Oklahoma City Thunder. He was not listed on the injury report but had received treatment on his knee after he said he overextended it on a play in Dallas' loss to the Los Angeles Lakers on Dec. 29. Porzingis informed the team's medical and athletic training staff during warmups that his right knee didn't feel right and he was pulled from the starting lineup.

Porzingis has missed all four games of the Mavs' current homestand. He expressed optimism last week that he'd return before the end of the homestand, but that is no longer the expectation with a back-to-back against the Lakers and Philadelphia 76ers looming on Friday and Saturday. He has been officially ruled out for both games.

The Mavs are 2-3 during the stretch without Porzingis, who is averaging 17.3 points, 9.4 rebounds and 2.1 blocks per game. Dallas has particularly struggled with interior defense during the elite rim protector's absence.

"Look, we miss him on both ends, but until he's back, there's no point in talking about what we're missing with him not being out there," Mavs coach Rick Carlisle said after Wednesday's loss to the Denver Nuggets. "A lot of teams are going through health issues right now. He's doing better all the time. There's nothing imminent on him, but he's doing better."