Bulldogs football manager Graham Lowe said the young midfielder's condition would be managed throughout the NAB Challenge series.

“Nathan sustained a rib injury during the game and we need to make sure that we manage that appropriately," Lowe told the club's website. 

"So we're going to manage his contact (training) through until about NAB (Challenge game) three and then we'll reassess him at that point and determine when he’s available to come back fully into playing and training.”

Hrovat, 20, is expected to miss the Bulldogs' next NAB Challenge assignment against Melbourne at Eureka Stadium, in Ballarat, on March 14.

But the midfielder is a chance to return for his club's NAB Challenge battle against Collingwood at Etihad Stadium on March 21.

Saturday's game against the Tigers produced its share of casualties, with the Dogs announcing that last year's best and fairest winner Tom Liberatore would miss the season after rupturing his ACL.

Young Bulldog Josh Prudden also sustained a mild form of concussion after a big hit late in the final term.

Lowe said Sam Darley and Shane Biggs were almost fit to rejoin training after dealing with minor knee complaints.

"Sam sustained a knock in training the day before and he’s had a few issues around his knee, a little bit of swelling so as much as anything just precautionary to manage him back in. He's come back good this week so he’s good to go," Lowe said.

"Shane had a little bit of bone bruising in his knee, through a contact injury. We're just working through to make sure that settles down in the appropriate way and managing his loads but he’s coming back into full training as well."