If he plays well with other children, it doesn't sound as though he has any deficiency in social skills. If he couldn't get along with other children when he does play with them, it would be another matter. Some children are, as you said, more independent and prefer to play alone much of the time. Give him plenty of opportunities to play occasionally with other children without making too big a deal of it. If possible, make arrangements in your neighborhood, family, church group, etc. for him to make a close friend of only one or two other children. Having such a friend may encourage him to reach out more readily and include other children in his play.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.