The England midfielder has signed a two-year contract.
F1 bosses have been forced to rejig the 2026 schedule due to the ongoing conflict.
The 23-year-old sealed victory on the second of two play-off holes.
Steve Borthwick’s team lifted their total of yellow cards for 2026 to 15 in eight Tests.
Root has begun a second spell in the role, replacing Ben Stokes.
Classy pair part of weekend entry as track returns to racing following discovery of hole in May.