The incident took place on Sunday near Huyton and Prescot Golf Club in Merseyside.
When police arrived at the scene, they found a man with injuries to his face and ribs.
Barton retired from playing in 2017 and has since had a couple of unsuccessful attempts at coaching. As a player, he represented clubs such as Manchester City and Newcastle.
The 43-year-old has a troubled past. In 2005, he broke a pedestrian's leg while driving his car. In 2008, he was sentenced to six months in prison for assault. He has also been suspended from various clubs for violent behavior both on and off the pitch, and convicted of "grossly offensive" posts on social media.
