Replacing RAID drive with used drive

[MDiSanzo]

I have a DL380G3 that needs one of the OS drives replaced. The two OS drives (# 0 and 1) are RAID 1+0. The system is running CentOS 4.5. I have the same kind of drive which was used previously in a different server, also running Linux. This drive still has data on it from it's original deployment. If I slap this drive into the server, will the RAID configuration cause this to be automatically mirrored off of drive# 0? That is the goal. I want to be sure that drive# 0 doesn't get overwritten.