What is this erupting on my right great toe?

[thesidmeister]

I have had these eruptions noticeable for the past 7-8 months on the plantar surface of my great toe. They were initially 2 in number (the bigger ones in the picture) and were embedded inside a few layers of skin, but were palpable and firm in consistency. Now they have ruptured(sort of) and have burst out from the layers underneath. The worrying thing is they have grown in numbers from 2 to multiple now and have also started appearing on the second toe(one) and the sole just beyond the joint of the great toe , as you can see in the picture. There is no discharge, these eruptions are dry, don't bleed and don't hurt unless I try to pull on them hard.
I play football(soccer) and dominantly use my right foot. I play casually and have been wearing rubber crocs and not proper boots while playing. I cannot find anything else I do more often with the right foot than the left apart from that.
I have attached a link below where I've uploaded a pic of the condition. Could anyone help?
http://pasteboard.co/5NOxmxjxW.jpg