RIO DE JANEIRO – Jose Aldo was at a press conference on Thursday to promote UFC 237, but there is still a chance that the former featherweight champion might not be able to make the fight.

Aldo (28-4 MMA, 10-3 UFC) was admitted to the hospital last week due to a bacterial infection on his knee. The antibiotics took longer than expected to work, and it seemed like his upcoming fight with Alexander Volkanovski (19-1 MMA, 6-0 UFC) could be in jeopardy.

Aldo eventually responded to the medication, though, and shortly afterward had his presence confirmed in Thursday’s conference to promote the event at Rio de Janeiro’s Jeunesse Arena. But it turns out Aldo still needs further confirmation to ensure his participation on the card.

“I went to the hospital on Wednesday and they wanted me to stay for one night to take antibiotics,” Aldo told reporters, including MMA Junkie, after the press conference at Copacabana Palace hotel in Brazil. “Then, the next day the antibiotics didn’t work, only on Friday when they changed it. At that moment, it did go through my mind that I might not be able to fight. I thought I was practically out.

“I’m not even saying I’m in yet. I can’t confirm that because I still have a medical evaluation to do. If the doctor lets me, I’m in. But we sent the video of the puncture they did on my knee, we sent it to (UFC matchmaker Sean Shelby), so everyone knows what’s happening.”

Aldo says he suffered the injury during wrestling practice, when he went for a double leg and suffered a bit of a “burn” on his knee. He kept on training normally and even went to practice the morning after, but he started feeling something wasn’t right with his body.

From Tuesday to Wednesday, Aldo said, his knee was badly swollen and throbbing all night. That’s when he went to the hospital. Aldo was discharged on Sunday and even showed up for practice the next day but now needs the green light from the doctors – as well as from manager and head coach Andre Pederneiras.

“I had a consultation scheduled today at noon, but I had to come to the press conference,” Aldo said. “But I’m doing everything (I can). I’m doing everything. On Monday, my knee was very swollen, I went to the gym and tried to train. I’ve been trying. I want to prove that I’m fine and I want to fight at UFC Rio. It’s not only up to me now, but the doctor’s evaluation and ‘Dede,’ as well, who has the final word.”

Aldo has suffered injuries that forced him out of fights before – including a pretty big one, against fellow former UFC champion Conor McGregor, at UFC 189. So why is he so adamant about making sure he’s able to compete on May 11?

Mostly, Aldo says, it’s because it’s in Rio. With just two fights left on his contract and plans to retire from MMA in 2019, the ex-champ wants to make sure he gets to perform in his adopted home.

“When the UFC moved from (original target city) Curitiba to here, the minute I knew I sent a message to (UFC president Dana White), and he confirmed me on the card,” Aldo said. “So I’m doing everything I can to be able to fight here.”

The good news is that the weight doesn’t seem to be a concern amid the stressful situation. Although the former champion doesn’t necessarily have an easy time making the featherweight limit, he believes the fact that the fight is at home will make up for the time the injury kept him away from the gym.

Aldo is adamant in that he has no interest in joining other MMA promotions and that, once he’s out of the UFC, he will also be out of the sport. And though he isn’t entirely ruling out a return sometime after 2019, he first wants to fulfill an old wish of trying his hand at boxing.

“I don’t want to do a super fight, I don’t want to challenge anyone,” Aldo said. “ I just want to start a career and see and, who knows, maybe fight for a title one day. Maybe because of my name, the fact that I am a former UFC champion, that might help shorten that path.”

When it comes to the time he has left in MMA, Aldo still isn’t thinking about reclaiming his majesty, as he is certain the UFC wouldn’t give him a stab at the title without negotiating a new contract. That means there’s a somewhat open picture when it comes to his last fight, which could include a long talked-about stab at the 155-pound division. But Aldo is now focused only on the task at hand.

Should things go to plan, that is still Volkanovski on May 11, and Aldo has a very clear idea of how he’d like that one to go.

“Because of his style, he’s very aggressive, so he’s a guy who opens himself up a lot,” Aldo said. “He comes forward all the time, so he leaves a lot of holes in his game. Of course, I’ll always picture the best way possible, which is a knockout. If it were up to me, it’d be very quick, just landing a knee and ending the fight.”

To hear more from Aldo, with the help of an interpreter, check out the video above.

And for more on UFC 237, check out the UFC Rumors section of the site.