Note:

Because the verb substitute (unlike German einwechseln) does give the information whether the player is substituted into the game or out of the game, you have to make this clear.

For instance, you might say:

Player A was substituted by the team's coach with Player B.

There really is no commonly used English for Einwechselung. The closest equivalent would be insertion or institution, but these terms do not exactly explain that another player was taken out. So for the OP's sentence you have to use verbs such as substitute in, substitute out or switch in, switch out.

So, the OP's sentence could translate as:

Because soccer players who are substituted into a game are often successful, they are considered a joker.

related discussion: Spieler einwechseln