RB Salzburg has already clinched its place in the next round of the 2018-19 Europa League, so if it wants to take it easy and send out a reserve team for this game - that is its right.
RB Leipzig might prefer to see Salzburg put a bit of effort into winning this match, since Salzburg must beat Celtic for RBL to have any chance of advancing to the knockout phase alongside its Austrian RB sibling.
One point is all Celtic needs to be sure of its own progress to the next round, though head coach Brendan Rodgers has promised his side will go for the win.
The outcome of this game and the one RB Leipzig will play against Rosenborg at the same time will determine to some extent the opportunities for playing time afforded Tyler Adams when he joins RBL in January. If there is still Europa League to be played in Leipzig, then there will be more minutes available to players across the squad. So Adams will likely have an eye on this match as he plans his move to Germany.
Per livesoccertv.com, here’s where to find the game if watching from the USA: