Along with the biomarker panels, Orreco’s algorithms also take into account game minutes, air miles traveled, sleep data and reaction times that are obtained from wearable devices used during practices.

The rules that allow players to opt out of blood testing are in place because regulating how teams use biometrics and the data such research produces — specifically whether the data belongs to the teams, players or the league itself — remains an evolving point of concern throughout the N.B.A. As a safeguard amid the rise of wearable technology in practice sessions, league policy threatens fines of up to $250,000 per team for the misuse of biometric data.

Yet Smith insists that the collaboration with Orreco has improved the Mavericks’ ability to track the onset of illness and keep players “more available” for games. In the 2016-17 season, according to data maintained by InStreetClothes.com, a website that tracks injuries in the N.B.A., Dallas players missed only four games due to illness — less than half the league average of 8.5.

The Mavericks then lost a league-low zero games to illness last season, when the league average was 7.1 games per team, according to the site.

“Does that mean we win more games?” Smith said. “Not necessarily. But it gives us a better shot.”

Still, with the sports and fitness world littered with treatments not supported by vetted published studies, some independent experts have their doubts.

Dr. Anthony Romeo, the chief of orthopedics at the Rothman Institute in New York and a former team physician for the Chicago White Sox who also worked with the Chicago Bulls, said he would maintain “a healthy level of skepticism” about Orreco’s work until it reveals more about the biomarkers it studies and the data being gathered.