It's possible however the main question is will he be interested?
Can he reach breeding size and produce sperm plugs? Yes likely if you start later in the season.
There are people breeding smaller males successfully however you do need to pay attention to your male, you could easily lose him as breeding can take it's toll on smaller males.
Bottom line you can never tell even if he is breeding size does not mean he will be interested.
Not trying to be a downer but making you aware that with animals there are never any certainties, all you can do is try and see.