I think it is a mistake to represent the goal as driving you forward, because the goal does not drive you forward, it may just sit there in your mind. It is your dedication to achieving the goal, and the will to act, which drives you forward, not the goal itself. The goal itself is a passive thing with no causal power. — Metaphysician Undercover
Goals are not passive things. They are active states of constraint. So they may not be efficient causes, but they are final causes. They shape the intentional space in which consequent decision making unfolds. If we have an image of the final destination, then that is how we can start filling in all the necessary step actions to get us there.
So let's take your example of throwing the ball. Suppose you're a quarterback, and the throw must be precisely timed. You hold the goal, to throw, and you hold the ball, to throw. At the exact right moment, you must pull back and release the ball. The motivating factor for the release is not the goal, because despite having the goal of throwing you continue to hold the ball, perhaps even to the point of getting sacked. The motivating factor appears to be the judgement "now", at which time the habit takes over and the throw is made. — Metaphysician Undercover
When playing fast sport, the decision-making has to be all pretty much habitual or automatic. Habitual responses are learnt behaviour - reactions ready to go - so can be executed in around a fifth of a second. Attention-level deliberation takes half a second at least. So it is much too slow to actually be in control while playing football.
The proper role of attentional-level goal forming is in the breaks in play. The "wait and get ready with a plan" moments. That is where the quarterback delays to become clear on his general intention during the next play. He has to start with a state of broad focus which shuts out everything he can expect to be able to ignore - like the cheerleaders prancing on the sidelines - so that his trained habits will be able to pick out all the rapid subtleties, like last instant reshuffles in the opposition defensive line.
Then the play starts to unfold and all his trained instincts can slot in according to a general intent. He is itching to pull the trigger on the throw. A conjunction of observed motions on the field hit the point where the habits themselves provide the timing information. The "go now" command is issued by the mid-brain basal ganglia in concert with the brainstem's cerebellum. The conscious brain can discover how it worked out a half second later as attentional-level processing catches up to provide a newly integrated state of experience. The quarterback can start thinking oh shit, or hot damn.
So the mistake is to try to assign thought, cause, motivation or intention to just one level of mental operation. And yet also, the general desire - neurobiologically speaking - is for a strong dichotomy to emerge.
Attention wants to do the least it can get away with. Everything that can be handed down the chain to learnt automatism will be handed down. But then that also leaves attention responsible for the very stuff that is the most critical or difficult or novel when it comes to "thought, cause, motivation or intention".
So a kid learning to play really does have to focus on the mechanics of simply timing a throw. There is no remaining capacity for thinking about the patterns of play likely to be unfolding on the field. But as a skilled player, even reading the game is something that doesn't need specific attention. Most of the effort has to go to just not getting distracted by cheerleaders, or whatever.
Motivation is thus dichotomous. It has both its generality and its particularity - the two levels complementing each other. You have to be governed by the constraint of some generalised intent. And then within that, you will be able to see all the particular steps needed to get you to that destination.
Action is not about summoning up the energy to do the bidding of reason. That is a mechanical metaphor - the psychology inspired by the industrial age when hot steam was needed to make the wheels turn.
Instead, a biological organism is always some host of spastic potential, itching and twitching, restless to be doing. Just watch a newborn squirming randomly. What it then needs is the focus so all that potential gets a clear direction that is useful. And over time, that intentionality has to become transformed into stable, reliable, habit. The ultimate goal is an economy of motion - achieving the most by doing the least.
Rather than motivation being about feeding the machine with more energy to get it to go harder, it is about learning how to reduce the informational load on acting so that doing what you need to do feels like an easy downhill ride - the flow experience of the truly skilled individual.
Who needs motivation to climb stairs or drive a car? Once the habits have been learnt, these dangerous and complex actions could not feel easier. We just get on and do them without having to break down any informational barriers.
Of course then there is real life where as soon as we have mastered the basic skills, higher level decision making gets piled on top. We even seek greater demands as unthinking and repetitive action gets boring. There are always new horizons to automate and assimilate to habit.
So when people complain about a lack of motivation to study, exercise, tidy their bedroom, whatever, it is because they face informational barriers - conflicted intentions - that make going in that direction too hard. They are really faced with the choice of either actually learning the appropriate life routines, or dealing with the possibility that its not actually something they believe in as a globally constraining life goal.