Celtics guard Evan Fournier struggled Friday night in his first game since recovering from COVID-19, missing all seven shots he took in 22 minutes of Boston's 109-104 loss to the Eastern Conference-leading Brooklyn Nets in New York.

Fournier, who hadn't played since April 4, talked afterward about the difficulty he had battling through the virus, which caused him to miss nine games.

"My experience -- where do I start? The first two days I was doing great, no symptoms at all, and then flu-like symptoms, high fever, really tired, fatigue, all that," Fournier said. "I honestly stayed in bed and slept for four or five days. The roughest part was ramping up the activity. The last two days of practice was really hard. I had moments where I was doing good and moments where I was exhausted.

"That's why you have to push through it. You have to do it to feel better. I don't want to spend another week just ramping up my activity and doing cardio and all that. I need reps with the guys."

Celtics coach Brad Stevens stuck with Fournier on the court down the stretch Friday night even as he was missing shots, both because the veteran sharpshooter still would earn the respect of the defense and because Boston simply needs him to get back in game shape as quickly as possible as it fights for positioning in the middle of the East playoff picture.

"Yeah, he's going to probably, very likely at least, going to struggle, and we just don't have time to practice," Stevens said. "He's got to play, he's got to get himself up to speed.

"Evan obviously couldn't make a shot, but I just asked him how he felt. He said he was pretty winded out there. So that was not a huge surprise. But it is good to get him those minutes, and I don't think he'll have many games like that."

Friday night was just Fournier's fifth game since Boston acquired him from the Orlando Magic a month ago, as he missed one game due to a false positive test before then testing positive for the virus and being forced to sit out. Boston used a large chunk of the trade exception it generated in the Gordon Hayward sign-and-trade to add Fournier, who should be able to give the Celtics the kind of versatile offensive weapon this team has desperately missed off the bench this season.

And, after missing so much time, Fournier said he was ready to get back on the court as soon as he could -- even if that meant his legs would be a little slower than if he'd taken more time to get himself right.

"I probably could have waited a few more days or a few more games to really feel better, but I just got here and I need reps to play with the guys and really understand the system offensively and defensively," he said. "So I only had two days of practice, and for me the most important thing is just to be out there. It's going to be hard obviously, but I have to fight through it and push through it because to me that's the only way I'm going to feel better at some point."