Male fertility?!?

Ok so I don't know if I'm a rule or an exeption ! I know just about there ecerything there is to know about womans fertilty lol...... But hardly nothing about a mans just looking to educate my self. How common is it for a man to have issues. My partner is 23 and we have  been ttc 8 months is it likely or not for there to be a problem with him? I currently undergoing tests and due to have a polyp removed so we've never really thought about him untill we had a convocation tonight Thankyou for any insite.