ok. . thanks to retrosheet.org, i am able to say that from 1997 on (because prior to that, he was set-up man for wetteland, and pitched 3 innings quite often) rivera has pitched more than 3 innings on precisely 1 occasion in that time (game 7 2003 ALCS). now, he's pitched 2 innings or more on many occasions, including one 2 2/3 inning outing during the 2000 regular season.
i will stand by overall view that if needed, i still would think that torre would send out rivera to at least start a 3rd inning of work, and that i find no problem with gardenhire letting nathan start a 3rd inning of work last night.