Jovanovic scored a double off the bench in Sunday's 2-1 victory at Melbourne City, with the 98th-minute-winner also giving him a share of the league's Golden Boot award with Auckland FC's Sam Cosgrove.
The 20-year-old had every right to be excited, but tearing his shirt off earned him a second yellow card, having been booked only a minute earlier for his part in an all-in melee.
Jovanovic said he "didn't know in the moment" when he was celebrating.
"I picked my shirt back up, and I started walking to the halfway line," he told Australian media.
"And then I heard the ref call my name and I saw him holding a red card, and I was like: 'Oh, my God'.
"I wish I could play the next game, but I know the boys will do the job."
Jovanovic's dismissal was also a surprise for Adelaide coach Airton Andrioli.
"I didn't even realise he got a yellow card in that sort of melee," he said.
"Obviously, he's now a little bit disappointed. We're also a little bit disappointed.
"But I'll take that any day of the week. Coming on, scoring two goals."