"Thank God I stopped playing [the next week] in Marseille and got treatment, I'd felt sick for a few weeks."
Recuperation in Croatia was far from relaxing as the world-class athlete was reduced to a near-invalid state while his battered body slowly healed. "I was in bed for weeks, until at least the early summer," he explained, and was beset by real worries about his future on court. "I was concerned that my career could be over.
"When I tried to walk I could only manage for 20 minutes, I had to start everything from the beginning," he recalled. "I'd try to run and really couldn't, it was a long, long process back. I had to start from zero after lying in bed with a fever."
After slowly trying to pick up his physical pace once doctors gave him the all-clear, he gradually regained his strength and began to consider a comeback.
But that scenario was derailed before the US Open as he won matches in Montreal and Cincinnati before the shoulder problem sent him back off court for an additional six weeks.
Healthy once again - but consulting strictly with his doctors on a regular basis - Ancic is reveling in his fresh chance.
"I missed the game so much, this is my second career," he said. "I'm still in a comeback. My shoulder is fine now, but I'm not yet back into the tennis routine. I can't yet train the way that I want.
"But every match I play is a bonus for me, I just want to try and finish the year with some wins, that's my only goal."
The Croatian added: "It's a tough period behind me, but it's behind me now. I believe in myself and I know I can play top tennis again. I'm glad to be over this career-threatening illness."
Ancic is not planning on any miracles for the remainder of 2007, content to slowly work his way back into form as his fitness permits.
"I hope to win a few matches and get ready for 2008. There are worse things in life than mono, I'm positive and I've just got to be patient."