DENVER — Colorado Avalanche forward Valeri Nichushkin has been placed in Stage 3 of the NHL/NHL Players’ Association player assistance program, the league said Monday, just hours before the team’s playoff game against the Dallas Stars.

Nichushkin, under the terms of the player assistance program, will be suspended without pay for a minimum of six months. He’ll then be eligible to apply for reinstatement, according to a release issued by the NHL and NHLPA.

No further information about why Nichushkin, who was on the ice with the team at morning skate, was admitted into the program was provided.

With Nichushkin out, Colorado, trailing 2-1 in the series to Dallas, turned to forward Jonathan Drouin, who returned to the lineup following a lengthy absence. Drouin had missed all of Colorado’s postseason games before Monday, after he sustained a lower-body injury in the regular-season finale on April 18.

A league source told ESPN that the player assistance program has four stages. Stage 1 is the first in-patient treatment for which there is no penalty. Under Stage 2, which follows a violation of the Stage 1 treatment plan, a player can be suspended without pay during the active phase of treatment and then become eligible for reinstatement.

Stage 3, which follows a violation of the Stage 2 treatment plan, carries a suspension without pay for at least six months, at which point a player can become eligible for reinstatement. Stage 4, after a violation of the Stage 3 treatment plan, carries a suspension of at least one year and reinstatement is not assured.

For Nichushkin, this latest absence from the Avalanche will be his third in the past 13 months.

The 29-year-old Nichushkin’s most recent absence from the Avalanche came in mid-January, when he was admitted into the player assistance program for undisclosed reasons. At the time of his absence, it was announced that he would be out for an indefinite period.

Nichushkin resumed skating with the Avalanche in late February before returning to the lineup in their 2-1 overtime win March 8 against the Minnesota Wild.

His first absence from the Avalanche came last April, when he missed the final five games of a first-round series that ended with the Avs losing to the Seattle Kraken.

At the time of his absence, the team said Nichushkin left for personal reasons. His absence came after police officers responded to a call at the team’s hotel in Seattle on the afternoon before the Avalanche and Kraken played Game 3 of their quarterfinal series.

A 28-year-old woman was in an ambulance when officers arrived, and medics were told to speak with an Avalanche team physician to receive more details.

The police report, which was obtained by ESPN, among other outlets, said the Avalanche’s physician told officers that team employees found the woman when they were checking on Nichushkin. The team physician told police that the woman appeared to be intoxicated and was too intoxicated to have left the hotel “in a ride share or cab service” and needed EMS assistance.

When the Avalanche returned for preseason camp, Nichushkin told reporters that “I think we should close it. It’s a new season right now. We have to focus on that.”

A first-round pick by the Stars in 2013, Nichushkin spent four seasons with the club that drafted him. He scored 23 goals and 74 points in 223 games, and never quite reached the heights expected of a first-round pick.

The Avalanche signed him at the start of the 2019-2020 season on a one-year deal worth $850,000. Nichushkin worked his way from a bottom-six role to become one of the team’s most important players. It led to him signing a two-year deal worth $2.5 million annually in 2020 before he signed an eight-year deal worth $6.125 million annually that started at the beginning of the 2022-2023 season.