Eyeshield 21, Whistle! Recommendations
Both are sports series about a young student at an unremarkable school who joins a sports team despite having limited talent for it and, through hard work, becomes a highly capable integral member of the team under the guidance of several upperclassmen of varied temperament and alongside his teammates and friends.
Both Eyeshield and Whistle have boys who never give up and apparently born with natural talent for a sport (Eyeshield - football, Whistle - soccer). The both have a genius senpai that support their kouhis (though in different ways) and coaches that were once professionals.
If you liked one you'll definitely like the other