Legs look a bit rough... and red.* Use the Search here on BYC to search for "Scaly Leg Mites" and / or "Picture of Scaly Leg Mites", or "What are Scaly Leg Mites".
Also, you might cut the spurs off. I am not sure how most do that, I know how my neighbor did it for me (for my rooster and even a hen that has some spurs). (I couldn't watch.)
You could also search "trimming spurs" and see what comes up. The Search tool here on BYC is very helpful when you want more info.
Blu Kote Spray is both a Germicidal and Fungicidal Wound Care -- and might help... (it stains, be careful) -- in the picture it looks like it could be a fungus (set in after the injury)? Maybe alternate it (Blu Kote Spray) with the treatments RhodeIslandeRedFan suggests, with the Betadine solution and Neosporin ointment. To treat both infection and other possibilities. But, if the spur is causing the injury, it will continue to repeat.
*If there is any pus, swelling, heat.... you might soak his leg(s) in a warm Epsom Salts bath and add some water soluable antibiotics to the water for a few days to take down the infection.
Good luck