yes and no
Yes-If one of you is attracted to the same sex
Yes-if one of you is attatched
Yes-if you have been friends since grade school
For every other reason, my answer is no. For a single man who is looking for marriage, he is looking for a woman he can make his wife. When men find a lady attractive, they want to get to know her better to see if she is someone they could see marrying. Friendship is always said to be the basis of a great love. When either one or the only is attracted, no they cannot be friends.
A man is looking for a woman he can marry, trust, and be vulnerable with. A man has to be able to trust you to be vulnerable. Also, men will not be vulnerable just because. Did he tell you how being left off the basketball team in 6th grade made him feel? Did he tell you that he is embarassed about the scar on his foot and the story behind it? Guess what? He sees you as a potential wife.
Also, women or men should not get upset with the other if they declare their feelings. If they don't feel the same, appreciate and respect it, and either move on, or don't.
I am sorry, I am not vulnerable with friends. If I tell you something that noone else knows, I either love you, am falling in love with you, or value and respect you a great deal.
If I am ever in love with you, I can't just be friends because one or both is then not being authentic because feelings are being withheld