I like him as a backup 1 /2 / 3 for the long term. I think his big strength is defensively he can guard three positions (1,2,3) and the offensive categories are just good enough to keep, especially the ball handling. You figure he's still got another pop in some of the key categories because of his youth, even though he's just outside of target training age. But he could easily end up proficient OD, tremendous / wondrous JS by 25.
You are right about the potential. . . however, there comes a time when some players just don't get any more training attention, and we should look at some players on our roster as being "complete." So unless you are training another player of similar position and height, I think he is the perfect role player. He's a guy you can leave alone,or start in the cup, or scrimmages, and he allows you to focus on training your bigs.
If you're training guards then I'd part with him, and I think he's worth at least 1 mil.
Do some check ups on the PL by sorting for a range of 2 below and 2 higher (so proficient to tremendous for JS for example), of his 4 highest categories, and see what the bids are for a player of comparable status.
And you're probably better off listing him in a few weeks once all of the bot teams clear out their retirees, this is usually my target acquisition time for new guys b/c owners are doing exactly what you are doing and cleaning house to try to stay competitive.