If a website claims to compress FIFA 14 down to 10 MB or 20 MB, it is almost certainly a scam or a broken, corrupted file. Data physics limit how much a complex game can shrink. If you want to customize your setup further, let me know:
Use 7-Zip to unpack the file. The output should be FIFA_14.iso (~1.8GB uncompressed). If the extraction fails, your download is corrupted. fifa 14 ps2 highly compressed
Plug the USB into your PS2, boot up , and refresh the game list. Safety and Avoidance of Malware If a website claims to compress FIFA 14