Eyre has linked up with the Saints this summer in hope of securing a career lifeline at Moorabbin following his delisting from Essendon at the end of last year.
The 20-year-old was cut from the Bombers after two seasons and no games at AFL level, having initially joined the club as a graduate of their Next Generation Academy.
The versatile tall was joined by former Carlton midfielder Liam Stocker as a Supplemental Selection Period signing hopeful at St Kilda this pre-season, with the Saints weighing up options for their two list vacancies for 2023.
While Stocker has successfully secured a second chance in the top flight, Eyre has continued to fight for a potential promotion with the Saints in recent weeks.
His hopes of further impressing senior coach Ross Lyon are understood to have taken a hit this week however, with AFL.com.au reporting Eyre is likely facing a stint on the sidelines after suffering a hamstring injury at training.
While the extent of Eyre's ailment is not yet known, there are fears the former Bomber could be out of action for the start of the 2023 AFL season if the setback is severe enough.
The SSP signing deadline is a fortnight away, meaning Eyre's prospects of a list spot with St Kilda will likely rely on his previous sessions with the Saints.
The Kilmore native has been an attractive asset for St Kilda to consider for the season ahead given their depleted key-position stocks to start the season.
Emerging tall Matt Allison was seen as a potential debut chance for the club's season opener before he too suffered a pre-season setback, with the Saints swingman ruled out for up to 20 weeks with a foot fracture.
Eyre is capable of playing as a forward target but might be best suited behind the ball as an intercepting option on the last line.
St Kilda will open their 2023 campaign against Fremantle at Marvel Stadium on Sunday, March 19.