Thomas was a genuine fast bowler, a rare sight in English cricket after the retirement of Bob Willis; apart from the raw pace, he was erratic and often had injury problems. At his best, he matched the speed of the fearsome West Indian pacemen on the tour of West Indies in 1985/86, but leaked too many runs with his wayward bowling. This difficult tour was followed by one Test in England, disruptive injury and an unsuccessful, and then a fruitless switch to play for Northamptonshire.

Thomas did not play for England again after he joined the rebel tour to South Africa 1989-90, defying the international sporting boycott of the apartheid state.

The West Indian batsman Viv Richards was notorious for punishing bowlers that dared to sledge him. So much so, that many opposing captains banned their players from the practice. However, in a county game against Glamorgan, Thomas attempted to sledge him after he had played and missed at several balls in a row. He informed Richards: "It's red, round and weighs about five ounces, in case you were wondering". Richards hammered the next delivery out of the ground and into a nearby river. Turning to the bowler, he commented: "Greg, you know what it looks like, now go and find it".^[2]

He is twice divorced, has a daughter Hermione and a son Will, and lives alone in Northamptonshire.