Keane is recovering from a knee surgery, having missed Ireland's recent Euro 2016 warm-up matches, and is expected to be out for around another month.
The 35-year-old former Leeds, Liverpool and Tottenham striker is a popular figure with the Galaxy, whom he joined in August 2011 and has since made more than 100 appearances as they won the Major League Soccer Cup three times.
The prospect, though, of not being able to go and watch her favourite player in action at the StubHub Center any time soon was just too much for three-year-old Xyla, who fought back the tears in a video which was posted online by her mother and later picked up by Keane himself.
The Galaxy subsequently invited the family to come to a game - where Keane was waiting to meet Xyla, who had drawn a picture for him and received a present of her own with a signed shirt before posing for pictures, his young fan this time all smiles.
"You made me sad with that video message, but I will be back soon," Keane said in the video of the gettogether, which was posted on the Galaxy website.
"I will be back in a few weeks, so next time I am back playing, you will have to come and watch me, and I will score a goal."