The 22-year-old was injured in Villa's final pre-season game against Watford in July and spent time in hospital, only making his first Championship start of the season in mid-December.
Now fully integrated back into the team, Grealish spoke to the official Villa site of the moment when he picked up the freak injury in an awkward collision with Tom Cleverley, and the immediate aftermath.
"When it first happened, I didn't think about the pain at all, I just thought 'the ball has gone, I'm going to be in trouble here'," Grealish said. "Then it sunk in. I felt I had been winded but 10 times worse. When I got up, I couldn't think about jogging, let alone running!
"I remember sitting down in the dressing room and we were 80 minutes in and I had the sharpest pain I've ever had in my life, I felt like I had been shot. I started shouting and then obviously we realised I needed to go straight to hospital. In spite of all that – and I laugh about it now – I was saying to the doctor on the way to hospital 'I will be fine for next week, though, right?'
"When they told me I had been cut in two places in my kidney, my first thought was for my health. First of all, they said it would be five months but, thankfully, after a scan in September I was back running the following month and training in November. Now it's great to be back doing what I love – and I intend on making up for lost time."
Grealish has made 11 appearances in all competitions so far this season.