I have worked in this company for a few years and have changed managers a few times due to organizational change. My current manager is a really cool guy and it was great working for him. There is an event coming up in a few weeks and I found out today that I might have to work with someone that I prefer to avoid in that event. 

I will not go into details but this person has a quick temper and this person has spread vicious rumours/gossips which caused me to be socially isolated/boycotted for 6-9 months when I first joined this company. Things are better now but mainly because I do make an effort to stay out of this person's way as much as I could and mostly keeping a low profile.

My current manager doesn't know what happened in the past because he works in another office all this time. I would to pull out from the event but it might send the wrong signal that I might lack team spirit or something. So is it safe or professional to tell your current manager about something that happened in the past or would it be better to keep mums about it and just go on with the event as though nothing happened? 

Additional info:

I didn't want to go into details because this person is in a managerial position and has shown bouts of anger, yelling and even intimidating other employees in the presence of everyone in the office. The only difference is that I was not directly yelled at but was told by another person to keep to myself at work or risk having negative impact on my work which went on for almost 6-9 months.