API Endpoint for offline tournament games?

I'm trying to use the Riot API to scrape stats for pro scene tournament games (this is for a uni class project). I can access the game info page for any given game in a tournament, such as this one: http://matchhistory.na.leagueoflegends.com/en/#match-details/TRLH3/1001380191?gameHash=43a46f49938bacca&tab=stats

However, where the region would usually be "NA1" or one of the other online regions, here it's "TRLH3", which the API doesn't seem to recognize. Is there any way to formulate a match API request for these games? Thanks!