The Swiss champions defeated Maccabi Haifa 3-0 on aggregate in the playoff round, while the visitors made it into this year's competition via a third-place finish in last season's Bundesliga.
Match preview
Young Boys are back in Europe's premier club competition after missing out last term, and they start by seeking a scalp of the fancied Bundesliga side.
Home advantage counted in the Swiss champions' favour en route to this season's group stage, as they defeated Maccabi Haifa 3-0 in Bern, having played out a goalless encounter in Israel.
Leipzig are a different kettle of fish, so Raphael Wicky's men must raise their standard to get off to a strong start in the group.
Their form going into Tuesday's meeting is promising, with Young Boys unbeaten in all competitions this season — winning six of their nine fixtures.
The recent run of five consecutive clean sheets in all competitions indicates defensive solidity, with Friday's 1-0 cup triumph against Xamax the latest in their sequence of shut-outs.
As for Leipzig, they seek to begin their European campaign positively after an acceptable draw for the Bundesliga side.
Marco Rose's men have responded amazingly to an opening-day 3-2 defeat by Bayer Leverkusen to claim three consecutive domestic victories, scoring 11 times and conceding one.
Summer arrivals Xavi Simons and Lois Openda have netted three strikes each after four league games, with the former setting up four goals for teammates.
The Red Bulls may have been blown to smithereens by Manchester City last season — and they have to contend with Pep Guardiola's men in Group G — but the broader context of their new arrivals settling must please Rose.
Leipzig losing Christopher Nkunku to Chelsea, Dominik Szoboszlai to Liverpool and Josko Gvardiol to Manchester City suggested a dip in performances and results was imminent, but the club's recruitment means they should navigate the group phase if current levels are maintained.
Young Boys Champions League form:
D
W
Young Boys form (all competitions):
RB Leipzig form (all competitions):
W
L
W
W
W
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Team News
Wicky has the full complement of his squad for the Swiss side's continental opener on Tuesday.
Young Boys have set up in a 4-3-1-2 this term, and a deviation from that approach is not anticipated for their Leipzig clash.
Despite the Bundesliga outfit's form, Rose has to deal with several absentees, with Lukas Klostermann doubtful for the Champions League opener due to illness and David Raum substituted at the weekend against Augsburg with a suspected injury.
Spanish international Dani Olmo's sprained knee could keep him out of action until late September, while Amadou Haidara and Andre Silva are not expected to return until the end of this month.
Willi Orban and El Chadaille Bitshiabu are missing out on Tuesday, with their respective knee injuries likely to rule them out until November.
Young Boys possible starting lineup:
Racioppi; Janko, Camara, Benito, Persson; Males, Lauper, Monteiro; Lakomy; Itten, Elia
RB Leipzig possible starting lineup:
Blaswich; Henrichs, Simakan, Lukeba, Lenz; Schlager, Kampl; Simons, Forsberg; Openda, Werner