The club's leading goalkicker in 2012 and 2013, Schulz made a bright start against the Bombers but was cut down in the third quarter when opponent Michael Hurley fell across his right ankle in a marking contest.
Click here for our full match coverage of the Dons v Port clash
The 28-year-old will be sent for scans but coach Ken Hinkley said he had suffered the same injury in 2013 and played through on his way to kicking 49 goals.
"We're pretty comfortable that he's OK," Hinkley said on Tuesday night.
"Jay did the same thing last year and played through no problems … I just asked Jay himself and he said, 'It's just like last year'.
"As I sit here right now I'm very confident about round one.
"We won't take a risk with him next week (against St Kilda at Alberton) … if he's fine we'll play him, but if he's not we wouldn't take a risk."
Schulz kicked 49.26 in 24 games last season and led the Power with 146 marks, eventually signing a contract extension until the end of the 2015 season.
He booted two goals on Tuesday night in a tall forward line led by Justin Westhoff, who was outstanding with five goals.
"He's at the right age as a footballer," Hinkley said of the 27-year-old Westhoff.
"He's really mature, he knows what he needs to do, he knows what makes him play well, he knows that part of his group of stuff that he does is he trains really hard every pre-season."
Essendon coach Mark Thompson said he wasn't concerned about the result on Tuesday night but he was concerned about his team's performance.
Click here to watch Mark Thompson's post-match media conference
"It wasn't our best night … we were very reactive, very slow to make decisions," he said.
"But I think in 10 days' time you'll see a sharper performance and then we'll really sharpen up for the start of the season."
New recruit Paul Chapman played his first game with the Bombers and impressed with a team-high 24 possessions, earning praise from Thompson, who coached him to three premierships with Geelong.
"That's the sort of guy he is, when it gets desperate he gets down and dirty," Thompson said.
"It was good that he got a few kicks. I was worried about him early."
Thompson said Michael Hibberd, who was substituted before half-time, had a minor hamstring strain and would be fit ahead of round one "pretty easily".
Brendon Goddard catches up with Jay Schulz after the clash at Etihad Stadium. Picture: AFL Media
Twitter: @AFL_Nathan
