Question on closer usage

For the more recent seasons that have a C rating for relief pitchers, what is the impact of using relievers with non C ratings in closer situations? Do they immediately become fatigued to an F8?
Community forum
http://forum-365.strat-o-matic.com/community/
http://forum-365.strat-o-matic.com/community/viewtopic.php?f=17&t=648879
coyote303 wrote:You absolutely want to have someone available with a closer rating for closer situations. In addition to a good closer, I always maintained* a cheap closer whose only bullpen role was second closer in case the main closer wasn't available.
*I use past tense because I now only play the 60s mystery league, which doesn't use closer rules. The 90s is the only mystery league which does. All of the recent single seasons use it.