McConnell's numbers as a starter vs. bench player:
First 9 games (starter): 20.0 min, 7.3 pts (.531 eFG%, .400 3P), 3.4 rb, 1.6 ast, 1.3 tov, 0.8 stl, 1.8 pf
Next 4 games (bench): 19.3 min, 5.5 pts (.553 eFG%, .250 3P), 3.0 rb, 1.8 ast, 1.3 tov, 1.3 stl, 1.3 pf
Next 12 games (starter): 28.6 min, 8.8 pts (.417 eFG%, .208 3P), 5.7 rb, 2.0 ast, 1.8 tov, 0.8 stl, 1.8 pf
Last 6 games (bench): 10.7 min, 2.5 pts (.300 eFG%, .000 3P), 0.8 rb, 0.3 ast, 1.0 tov, 0.5 stl, 1.2 pf
But his slump started while he was still a starter.
First 8 starts after return to starting lineup:
29.4 min, 10.0 pts (.477 eFG%, .313 3P), 6.3 rb, 2.9 ast, 2.1 tov, 1.0 stl, 1.8 pf
Over his last 4 starts before returning to the bench:
27.0 min, 6.3 pts (.316 eFG%, .000 3P), 4.5 rb, 0.3 ast, 1.0 tov, 0.5 stl, 2.0 pf
His shooting was off, his assists disappeared, and his fouling went up. It's possible during this time he was afraid that Baker's improving health would mean a loss of his starting spot, and he began pressing too much - but it began before he started coming off the bench to close the season, and spiraled quickly downward.