Relief Pitcher Usage

What are the rules regarding the use of relief pitchers? I had mistakenly thought relief pitchers could not throw three appearances in a row.

I am in a 1977 league and have Willie Hernandez who is an R3 and pitched in each of the 3 games last night in relief - 1.2 innings, 1.1 innings and 2 innings. just wanted to understand the max usage / inning / appearance limits, etc.

Thanks for your help.

There's no actual rule that a reliever can't pitch 3 games in a row. If he pitches 2 in a row, then he's automatically fatigued for the third game. As such, Hal will try to avoid using him... but there could be any number of reasons why Hal felt that Hernandez was the best choice in that situation.
As for limits on innings, appearances, etc., there are none in the 365 game. You'll occasionally see a RP pitch 300 innings.

Thanks for the reply.

No problem!