val sender: Connection = ???

// #1
sender match {
  case p: ProxiedPlayer =>
    //code
  case _ =>
}

// #2
Some(sender) collect {
  case p: ProxiedPlayer =>
    // code
}

// #3
object Match {
  def default: PartialFunction[Any, Unit] = { case _ => }
  def apply[T](x: T)(body: PartialFunction[T, Unit]) = (body orElse default)(x)
}

Match(sender) {
  case p: ProxiedPlayer =>
    // code
}