Felton's deal is for 2.9 million more than Nelson's - we may not have been able to fit him into a TPE, but even if we could, he'd be more expensive to have, more expensive to buy out, more likely to take his player option due to his injury, and harder to trade even if he wasn't injured.
You have to put a lot of value in feeding minutes to Pressey, whose ceiling is a fringe backup PG, to see that as a better move.