Conditioning when injured


So I strained my LCL back in december. Since then, I have not ran, which has been detrimental to my endurance. I have lost several matches that I should not have lost, and the main reason was that I gas out and have no endurance to last. Does anyone have any exercises that I could do (with a strained LCL) that will increase my endurance level in relation to folkstyle wrestling? Thank you