It's a big blow for the Saints, who have called up Darragh Joyce as a replacement.
Howard's late withdrawal is one of several changes St Kilda are making ahead of the crunch clash in Perth. The club has already confirmed two other changes prior to today's news.
First-round draftee Nasiah Wanganeen-Milera has been guaranteed a proper debut after being the medical sub last week.
The club announced Howard's withdrawal on their website on Friday afternoon, however no further information is available.
He will be replaced in the line-up by Rory Atkins.
Lachie Weller will miss our Round 2 game against Melbourne tomorrow night after entering the AFL Health and Safety Protocols. Rory Atkins comes into the side and Chris Burgess has been added to the emergency list. pic.twitter.com/NeEAA0MF4T
— Gold Coast Suns (@GoldCoastSUNS) March 25, 2022
It's a trend that's beginning to look like it will drag on all season; West Coast Eagles coach Adam Simpson announced on Friday that they will likely "lose 12 players from the Round 1 team" for their clash with North Melbourne this Sunday.
The AFL had been prepared for COVID to wreak havoc with its season, ensuring all clubs could add supplementary players to their list in the event of players being ruled out due to COVID protocols.