St Kilda has suffered several injury blows ahead of its match against North Melbourne.

The Saints were defeated by Fremantle to the tune of 37-points on Sunday and will need to keep an eye on some key players.

Small forward Jack Lonie will need scans on his leg after hurting it in the first term. He managed to play out the game but was hampered and had to spend a large portion of the second quarter on the bench with medical staff.

In his first-year, Lonie has played 16 games and kicked 12 goals.

"It's a lower leg issue. Hopefully it's just quite a significant bruise, possibly to the bone area, but we'll get scans and see where that ends up," St Kilda coach Alan Richardson said.

Half-back Daniel McKenzie had to be subbed out of the game with concussion and Shane Savage left the field in pain with a hip/back concern.

Despite the lack of players and rotations, the Saints managed five goals to one in the final term and avoided a heavy defeat.

"It makes the finish of the game all the more impressive really, given the state the group was in," Richardson said.

"It was very frustrating and disappointing for the players involved, but to the guys' credit they hung in there."

Richardson said while a tough end of the year is in store, he doesn’t want his men limping to the line.

"That'd be really disappointing if that were to happen. That would be blokes just falling away and almost giving up. I'd be surprised [if that happened] given what I've seen of the group so far," he said.