playerObj.yProperty().bind(player.yProperty());

pane.setOnKeyPressed(e -> {
        switch(e.getCode()) {
            case UP:
                player.goUp();
                System.out.println("player Y property: "+player.yProperty().getValue());
                System.out.println("playerObj Y property: "+playerObj.yProperty().getValue());
                break;
        }
    });

player Y property: 245.0
playerObj Y property: 250.0
player Y property: 240.0
playerObj Y property: 250.0
player Y property: 235.0
playerObj Y property: 250.0