At 9 p.m. Sunday, the Toronto FC goalkeeper went from husband to parent of three in one fell swoop as wife Evelyn delivered triplets.
Kocic skipped practice Monday to spend time with his newly expanded family. But he was back in training Tuesday with a beaming smile.
Mother and babies are still in hospital but doing well.
"She's doing great. She's started walking now," a bubbling Kocic said after practice. "She's a fighter, she's a great woman. The gift she gave me, it's unbelievable."
The oldest is a girl named Soleil. Then there are two boys: Leo (or Lionel as in Barcelona star Lionel Messi) and another Milos.
The babies, who weighed five, four and three pounds, will remain in hospital for two weeks. His wife is expected to be released Wednesday.
"For me it's still kind of the same," Kocic said. "Not much change except I'm busier than usual. I guess when they come home, it's going to be a different story. I'll have to deal with a lot of crying and stuff, but it's all good."
Kocic was prepared. "Strollers are here!!!," the 27-year-old from Serbia tweeted, along with a photo of a three-seater.
There is no history of triplets on either parent's side.
"Total surprise," said Kocic. "All natural."
They learned the news during an ultrasound when the doctor told them there were three heartbeats.
"We were like 'OK, is it a baby with three hearts?'" he recalled with a giggle.
No, just three babies.
"So we were in shock for a while," Kocic added. "But you get used to it, I guess, to the idea of expecting triplets. Now they're here, so it's life-changing for sure."
The delivery date was supposed to be Sept. 20 or 24 but the trio came early. Kocic was slated to go fishing Sunday but the conditions didn't look good so he was headed home when he got the call.
He was in his fishing gear as he headed to hospital.
The Kocics have a good support group in Toronto. Evelyn's mother and sister live nearby and Kocic's mother will be arriving soon from Serbia.
The rest of the relatives overseas may still be celebrating.
"A lot of drinking (Monday)," Kocic said happily of his family back home.
Kocic is slated to start Wednesday against the visiting Chicago Fire (13-8-5) although manager Paul Mariner said that may change depending on his family situation.
"There's a lot to go through," Mariner said. "Twenty-four hours is a long long time with three brand spanking new children. We'll wait and see but at the present moment he's playing."
"It's a massive change in his lifestyle though that's a certainty," he added.
A tie or loss Wednesday will officially eliminate Toronto FC, the league's worst team at 5-16-6, from playoff contention.
Toronto has not won in the league since July 18 when it beat Colorado 2-1. The team is 0-5-2 in MLS play since.
"We haven't won for a couple of months and it's killing us," said Mariner. "We want to win."
Toronto is missing midfielder Terry Dunfield and fullback Ashtone Morgan (Canada), defender Dicoy Williams and forward Ryan Johnson (Jamaica) and midfielder Oscar Cordon (Canada under-20). All are on international duty.
But Irish defender Darren O'Dea and Bermudian goalkeeper Freddy Hall and attacking midfielder Reggie Lambe are back in the fold after playing for their country.
Mariner was less than happy with the Football Association of Ireland after O'Dea spent "15 hours in economy" returning from a World Cup qualifier in Kazakhstan.
To make matter worse, O'Dea had a middle seat.
"I don't want to sound elitist but he didn't come back in the greatest shape on Sunday night," said Mariner. "So that's a worry."
Hall played the last four games for Toronto in goal as Mariner looked to evaluate talent on his roster.
The Fire have already defeated Toronto twice this season, 3-2 at BMO Field on April 21 and 2-1 at home on Aug. 4.
Chicago hosts the Montreal Impact on Saturday.