I'm a massage therapist and a runner and would recommend a massage to anyone (not just because that's my bread and butter
). However, a word of caution for a massage so close to an event. You do need a very well qualified therapist who knows what they are doing. Make sure that you tell them when is your next event. A good therapist will most probably be reluctant to do a full on sports massage and will just give you a relaxing and soothing massage. Anything too vigorous can have detrimental effect on your race.
While massage can be beneficial some therapists seem to think the harder they 'hit' you the better and it can leave you in pain for weeks. I've come out from sports massage not being able to run properly for 2 weeks. That should not be case.
Also make sure that you tell your therapist when the pain is too much. No pain no gain theory doesn't necessarily work in massage. The pain should be somewhere around 6-7 on 10 point scale. So you shouldn't be in complete agony.
Post event massage, depending on the damage done on the muscles will also not be overly strong. It should help to flush out the waste products (i.e. lactic acid build up); you should be able for good going over couple of days after the race.