Having started out in his homeland with Benfica, Sousa's illustrious playing career saw him win this competition on two occasions with Juventus and Borussia Dortmund, and the 44-year-old remains one of only three men to have won back-to-back finals with different clubs.
After leaving Dortmund in 1997, Sousa played for Inter, Parma and Panathinaikos before calling it a day following a stint at Espanyol.
Sousa revealed this week that, on more than one occasion, he came close to joining Porto, who visit Basel in the first leg of their last 16 clash on Wednesday.
"I was close to signing for FC Porto, it's true," he told A Bola. "There was that possibility before and after Espanyol.
"However, in the latter case, I was even closer to return to Benfica.
"The only contact I had with the president of FC Porto was when I arrived at Juventus. He was in Italy to see how the ticketing worked at the club and in Italian football and then we had the opportunity to talk.
"He acknowledged the admiration he had for me and said he wanted to see me play at FC Porto, which made me very happy. But it never happened."
Basel progressed as runners-up from a tough group that also contained Real Madrid, Liverpool and Ludogorets Razgrad, while Porto were comfortable in topping Group H, but coach Julen Lopetegui knows his players must be at their best.
"This [Porto] is a team that deserves its qualification for the knockout stages following a group in which they beat Liverpool," he told UEFA.com. "This team gave Real Madrid a hard time in Switzerland.
"They have experience and also did very well last season. It's a team packed with talent.
"We have to be at our best in terms of intensity and concentration if to have a chance to qualify."
Both clubs have only reached the Champions League quarter-finals on one previous occasion, with Basel - who will be without the suspended Fabian Schar - suffering a 7-0 aggregate defeat to Bayern Munich when they last reached the round of 16 in 2012.
Porto, meanwhile, have lost just one of their last 14 European fixtures at home and away.
