First, you have to show interest in the sport. In order to pull this off, you don't really require any special knowledge. Just be there and go with the flow. For instance, suppose you are watching a cricket match and don’t know what the players are doing on the ground, just follow the signals of your friends. Show that you are also watching the match with them and have an interest in the game.
Be a fan
It is extremely important for you to pretend that you are a fan of a player or a team in the sport. If you want to show that you are a follower of any specific sport, you must be a fan of someone in a particular team. For example, if you are watching football with your friends or having a discussion with them about it, you must pretend that you are a fan of a team and a footballer. If you don’t know any particular names in the sport, just become a fan of player or sportsman who you know by name.
You must be attentive during the matches, competitions and other sports events while you are with your friends. Moreover, try to grasp things from the comments of your friends in the surroundings. In this way, you will be able to participate in the discussion which will eventually help you in faking an interest in sports.
Follow the cheers
If you are with your friends, follow their cheers and be a part of celebrations. You should never feel shy to express your feelings regarding a particular sport. Just enjoy your time with your friends.