Jacobs made his debut for the club in round one of the NAB Cup, but pulled up lame in a running drill on Tuesday morning and has been ruled out of the Crows' clash with Fremantle at Thebarton Oval on Saturday.
The ex-Carlton rookie will have scans to determine the extent of the damage, but is expected to spend up to three weeks on the sidelines.
The 203cm ruckman has endured a frustrating run with injury since joining Adelaide via the AFL's exchange period in October.
He suffered a similar hamstring strain prior to Christmas and missed the club's internal trial earlier this the month after splitting the webbing in his hand.
The Crows' ruck stocks were dealt another blow on Tuesday, with utility Brad Moran ruled out of the game against Freo with a back complaint.
Reigning best-and-fairest winner Richard Douglas (back) will also be rested this weekend, while David Mackay (groin) and Bernie Vince (knee) completed training and are a chance to return on Saturday.
The injuries to Jacobs and Moran open the door for incumbent No.1 ruckman Ivan Maric to shoulder the majority of the ruck duties this week.
Maric, who has led Adelaide's ruck department for the past three seasons, said he'd welcomed the internal competition provided by Jacobs and a fit Moran but that he would use the game against Fremantle to try to cement his place in the team for round one.
"I'll be focused on being the No.1 ruckman at this club," Maric said on Tuesday.
"Every since day one there's been competition and that's what I love about the game. I've thrived on that for six years. With Sammy coming into the club and Brad having his leg right it's great.
"There probably hasn't been a ruckman here over the last three or four years that has really stood out. There are guys that have played consistently, but to be honest I probably haven't displayed dominant ruckwork.
"It [the No.1 ruck spot] is always open every year, and the person who takes their opportunity and plays good footy over the next few weeks will get rewarded."
Maric has also focused on improving his forward line work in the wake of the changes to the AFL's interchange rules.
With suggestions that the changes will eliminate the need for a second ruckman in the modern game, Maric called on the AFL to consult the playing body before making alterations that could potentially affect the livelihood of some players.
"When I started playing football when I was 16 all I heard was how football is a game for all shapes and sizes, but maybe with this rule it's putting a bit of a limitation on big guys," he said.
"The AFL changes a lot of rules … but this one has had the most impact on the players and their lives.
"The AFL probably could've gone about telling us in a better way - I found out through the TV. We spoke about that with Andrew McKay when the umpires came down and they're aware of it and they're going to consult the players a lot more in the future, which is really important.
"We just want to feel like they care about us and like they're thinking about us."
Ivan Maric is a $240,300 ruckman in the Toyota AFL Dream Team competition
