The 26-year-old midfielder was one of a flurry of signings at Notts along with former Manchester City and England youth captain Ed Francis, 21, and midfielder Aaron Nemame, 23, who has joined from rivals Torquay United.
Magpies’ manager Ian Burchnall described the Bucks as a good test ahead of the season opener in three weeks, and Roberts capped it when he cut in off the right wing before striking a powerful left-footed shot that beat Russ Griffiths in the Bucks goal to his left.
Second-half goals from Dan McCrory and star man Kyle Bennett earned victory for National League Notts County but Coalville, in their first meaningful game since November, certainly played their part in an end-to-end encounter.
The former Scotland and Rangers defender resigned from his position as the Magpies assistant head coach on Monday following the incident in their 1-1 draw last weekend at Altrincham, during the club’s boycott of social media over discrimination.
After trailing by two goals, United pulled one back through Connor Lemonheigh-Evans before they found themselves a man down after sub Josh Umerah received his marching orders for a second bookable offence, only 20 minutes after coming on.