The pressure to excel in studies is in order to earn a good living. If u take care of them financially with a decent monthly stipend and than offer to send them for coaching courses after their playing career than they will know there is another option to studying like crazy.
The main problem is the culture. Singaporeans are not known to worship or support local sports talent or any kind of non-academic talent, especially when they have not made a name for themselves yet. They are only willing to open their wallets for overseas big stars, same goes for other areas like the arts. The main cause is how the nation-building was carried out over the last few decades. There is no unity in the people. Trust me, all the effort spent on NS is truly useless if war really does break out. If the hatred of PAP is indeed ubiquitous, it may be the best thing PAP has ever done for Singapore, by creating the sparks for a burning passion for solidarity.