We've heard pretty much every excuse as to why Colin Kaepernick is still a free agent. The speculation began with his politics, then it was his poor football play, then it was his demands and now it's reportedly his diet.
The quarterback changed his diet to vegan after dating television star Nessa Diab. She revealed last offseason they had gone vegan together as a couple, and the quarterback later admitted himself he had switched to the diet.
Most storylines on Kaepernick last season dealt with his refusal to stand for the anthem, but there was actually a bit of commotion regarding him becoming vegan. He had a noticeable weight loss because protein (most commonly ingested through meats and dairy products) is crucial to maintaining muscle mass.
This was all before the season really began though, and Kaepernick played just fine in 2016-17 to the point where teams shouldn't really be concerned about his diet. Other NFL players have gone vegan, including Tony Gonzalez and Arian Foster, and were able to continue playing.
Tom Brady — you may have heard of him — has an almost-vegan diet, as revealed by Bleacher Report earlier this year. He is vegan for almost the entire year, but adds in lean meats like chicken during the winter months as a way to maintain muscle mass.
There are probably several reasons why Kaepernick remains a free agent, but his diet is probably the least likely one.