Howden is dealing with an illness and may not travel with the team for Thursday's matchup with the Blues, Danny Webster of the Las Vegas Review-Journal reports.
Howden scored a goal on five shots and added two PIM in Monday's 5-4 shootout loss to the Blues.
Howden scored a shorthanded goal in Saturday's 6-3 loss to Edmonton.
Howden signed a five-year, $12.5 million contract extension with the Golden Knights on Friday.
Howden scored a goal on three shots and blocked three shots in Saturday's 4-3 overtime loss to the Panthers.
Howden scored an empty-net goal on four shots in Wednesday's 8-4 win over the Avalanche.
Howden scored a goal on three shots in Tuesday's 5-4 overtime loss to the Predators.
Howden (upper body) will be activated from injured reserve ahead of his return to the lineup Tuesday against Seattle, Jesse Granger of The Athletic reports.
Howden (upper body) was put on injured reserve Friday, according to Danny Webster of the Las Vegas Sun.
Howden's slated to miss Thursday's game against Toronto due to an upper-body injury, Adam Hill of the Las Vegas Review-Journal reports. The team regards him as day-to-day beyond that.