PPG makes a primer just for that - SX1060. Many of my customers have rolled primer (K36, NCP250 ) on spot situations for years and have had no problem at all. The carrier portion of the solvent is contained in the solvent you use for reduction to spray - something you will not be doing for a roll on application. It does have it's disadvantges though. You tend to get ridges along the edge of the roller (foam) which can make it a pain to sand level. That's a big reason it only gets used for very small areas. Also the smell is just as bad as if you would have sprayed. Ventilation is still very important. I have rolled JP202 and have had very good results so if it is your only option for the moment have at it. Keep it to one or two coats at most. Give it extra time to cure before sanding, you'll find it will powder just as nice.

Have fun,
Dan