St. Louis Blues' David Perron (57) passes around Edmonton Oilers' Duncan Keith (2) during the second period of an NHL hockey game Wednesday, Dec. 29, 2021, in St. Louis. (AP Photo/Jeff Roberson)

The group of St. Louis Blues players sidelined due to COVID-19 continues to grow.

The team announced on Tuesday afternoon that forward David Perron has been placed in the NHL's COVID protocols. He becomes the sixth Blues player currently in the protocols, joining forwards Brayden Schenn and Vladimir Tarasenko and defensemen Colton Parayko, Scott Perunovich and Jake Walman. He's the 20th player the Blues have placed in the protocols this season.

Defenseman Calle Rosen was also added back to the taxi squad Thursday to give the club some defensive depth as it deals with the effects of COVID.

This is the latest development in a frustrating season for Perron, who previously missed 11 games due to an upper-body injury. The 33-year-old forward has eight goals and 12 assists in 25 games.

The Blues have just 10 healthy forwards remaining on their active roster, though James Neal and Nathan Walker are on the taxi squad and could be promoted before Thursday's game against the Seattle Kraken. It's also possible that Tarasenko, who entered the protocols last Thursday, could return by the time the Blues return to action.

Rosen, 27, is back for his third stint on the taxi squad since the NHL permitted clubs to begin carrying an extra group of non-roster players in late December, and he could be pressed into duty on Thursday if the Blues don't get any defensemen back from the protocol list. He has two assists with a minus-1 rating in five games with the Blues this season.