"If"? Have you got one? I'm guessing that you have.How old is the pup? Does he (or she) come when called? If not, you'll get nowhere. Does he play fetch? If not , you'll get almost nowhere. A simple book on puppy training will show you how to achieve both quickly.
Basic rule is that the dog will do whatever it finds attractive. So, if, for example, it won't come when called from some delightful sniffing you have to make what you offer more attractive than the sniff! Same applies to footballs . With puppies this is easier than with older dogs.All are born with something of their chase and hunt instinct and moving footballs arouse both.
Go equipped with favourite toy(s). Always make a big fuss of the pup when he comes and always call in excited tones for good things, so he associates the tone of voice with happy rewards. Now for the footballs. Have him on a lead, As soon as he sees, and just as he starts to look interested in, one, say NO! in a firm voice,reinforcing that with a slight tug on the lead so he has your attention. Repeat No! Then pause briefly, distract him, with the toy and praise when he is distracted, and lead him away a bit. You are trying to build the image in his mind that you are more attractive than the unwanted behaviour, it is better and more rewarding not to do it. He should lose interest given time and repetition. He wants to please you, too, though that may not be obvious ! The gruff No! is less pleasant than the distracted praise and toy,and he knows which option pleases you
Off the lead the tactics are the same, but you can distract him as soon as he shows interest by showing the toy and throwing it some short distance, so he comes to that , he remembering the established preference, Then hold him and praise.
How long does it take? If you stop it when it starts, almost no time. Once he has the behaviour established, it takes longer, but with a pup it still shouldn't take long; you have to be persistent and consistent.