However, the 25-year-old full-back, on loan from Aberdeen until the end of the season, believes the performances against Valencia and United at Ibrox, where they drew 1-1 with the Spanish club and lost only to a Wayne Rooney penalty against the Red Devils, will stand the Scottish champions in good stead regardless of who they face in UEFA's second-tier club competition.
"We have shown in the Champions League that we can compete with anyone really," Foster said.
"Obviously there are teams that are very dangerous in the Europa League but I don't think we would fear anyone and getting one of those two sides would make for a great atmosphere both at Ibrox and down in England.
"I don't think there is any point in us being in the competition if we are not confident.
"I think we showed, especially at home against Valencia - and we were unlucky against Man United - that we can compete against these top, top teams.
The Europa League will resume in February.