Yes and no. Obvious non - UK background/heritage? And/or live in a big (multicultural) City? Then it could well be fine, but otherwise I'd consider if your son is likely to have the confidence to pull it off (as it's a very uncommon name - no records I can find of it being used for a UK born child, although they only record names used more than twice each year). Plus it might get shortened to "Sal/Sally", which could also be something to consider.