Henry Thomas may never live this down, if he ever remembers what happened.
The Oxford captain lasted all of 22 seconds in the Varsity match against Cambridge, at Twickenham, on Thursday.
Wales and Lions inside centre Roberts, who is studying medicine at Cambridge, had seven inches and four and a half stone on his opposite number in a mismatch for the ages.
Roberts got his hands on the ball in the opening forays and Thomas just happened to be in the wrong place, and the wrong stance, at the wrong time.
What happened next was brutal.
Thomas was slow to get up and needed prompt treatment.
Amazingly, for a Varsity level encounter, play steamed on without a break for three minutes until the ball was eventually knocked on.
By that stage, a dazed Thomas was already on the sideline and wondering what hit him.
Roberts himself had to go off with a dead leg in the second half – something his new club, Harlequins will not be pleased with.