Wales and British & Irish Lions centre Jamie Roberts will play for Cambridge University in the Varsity match against Oxford at Twickenham on 10 December.
The 28-year-old, who is set to join Harlequins that month, is studying at Cambridge part-time for a Masters degree in medical science.
Following this autumn's World Cup with Wales, he will play for the university before joining Quins in mid-December.
Roberts agreed to join Quins from French side Racing 92 in May.
"I was certainly keen on education in school and I would have loved to come to Oxford or Cambridge as an undergraduate, but that wasn't possible," Roberts told BBC Radio Cambridgeshire.
"Coming to somewhere like this as an experienced international player is a challenge in itself. You have to earn your place in the side and earn the respect of your peers like any other club.
"It's what I can give as far as my experience on the international stage. Cambridge have lost the last five and it will be a challenge for me personally to help the team win the next one.
"No team has won it six times in a row, and we have to stop Oxford doing that."
He will become the first current British & Irish Lion to play in the Varsity match since Hugo MacNeill in 1983.
Former Australia lock Dan Vickerman was the last man to captain the Light Blues to victory in 2009.