After Gobert, I honestly think you could make the case for any of Rubio, Hood, Favors (assuming good health), or maybe even Ingles as the 2nd best player on the roster as it stands now.
A couple of metrics for each over the past season:
Rubio: 16.8 PER, 6.1 WS
Hood: 12.4 PER, 2.6 WS...