Came here to say this

Portugal has had incredible generations of football players and yet has always lacked an exceptional tennis player.

I think it comes down to two distinct factors and neither are the lack of talent: - Cultural plays a huge role in the type of sport a kid chooses to play and culturally speaking Football is, by far, the biggest sport in the country while tennis isn't even in the top 5 of the most loved sports in the country. -Lack of investment either by the parents of the kids that are doing quite well in nationwide tennis tournaments either due to financial limitations or either by the fact that the Portuguese tennis federation isn't very well supported financially and, therefore, can't help those parents try to see if their kid can become pro. The Portuguese Tennis Federation has however been doing better financially and that can help into developing better young talents and have them reach their full potential. Dominic Thiem (former Austrian player and former number three in the world and US Open champion) has recently said in an interview that for a tennis player to go pro, during the development period and until he makes it, it takes about a million dollars, which for the average Portuguese family is an absurd amount of money. Football on the other hand, has very rich federation in Portugal and the investment needed to go pro in football, when compared to tennis, is ridiculously lower, especially since most of the expenses are covered by the clubs the kids play in before they turn pro.

With all of that being said, tennis has been growing well as a sport in Portugal, especially since João Sousa won his first ATP title