Smeltz was lively in attack and found the back of the net for the first time this season after making his return from a five-week stint on the sidelines with an ankle injury.
But interim Glory coach Kenny Lowe said the A-League's all-time leading goal-scorer would remain on the bench for next Friday's home clash against Brisbane Roar and possibly the week after against the Western Sydney Wanderers.
"He's been on at me for about three weeks to play, but for three weeks he's been hobbling around like a 94-year-old," Lowe said.
"We've got to drip-feed him in. The worst thing that's happened is he's banged two in and he'll be coming in and telling me he can play the whole game against Brisbane.
"We've got a duty of care and a moral responsibility to make sure that when (players) come back (from injury), they can do what they can do."
Lowe was coy on when marquee signing William Gallas would return from a calf injury that has kept him sidelined since late November, but said the former French international would also return via the bench.
Glory's win over Heart was the club's second in a row and third clean sheet from four matches under Lowe since he took over from the sacked Alistair Edwards.
Lowe was appointed on interim basis for the rest of the season and will leave it up to Perth owner Tony Sage to decide if he stays on permanently.
"That's for other people to decide, it's got nothing to do with me," Lowe said.
"If the big fella thinks I'm suitable, I'll do it. If not, someone else will come and do it. We've always said we'll come in, we'll add value and we'll try and show people we're good at what we do.
"It's like anything – you just do what you can do and enjoy it. I'm an engineer by trade and I enjoy that line of work, but I'm not in a particular rush to go back there."
Lowe also confirmed the club had terminated the loan contract for injured Japanese winger Ryo Nagai and will target a replacement player during the January transfer window.
"Ryo has got a hamstring injury and unfortunately he's going to be out for a while," Lowe said.
"We'll need all hands on board because we have a very thin squad. We can't really wait five or six weeks for someone … so unfortunately we'll use that visa spot maybe for another player."