Celtic will have improved as a team if they finish third in their Champions League group and qualify for the knockout stage of the Europa League, according to former Hoops striker Alan McInally.
Celtic are currently third in Group B behind European giants Paris Saint-Germain and Bayern Munich, and Brendan Rodgers' side must avoid defeat against the German champions at Celtic Park on Tuesday night if they are to maintain their challenge for top-two spot in the group.
The Hoops were comfortably beaten 3-0 in the reverse fixture earlier this month and McInally believes his former side will always struggle to compete with European football's elite clubs.
"It is a money thing when you get to this level," said McInally. "You do have to have that investment in your football club if you're going to be that aggressive at it.
"We've seen teams try to do it and come unstuck. Most of them are floundering in the Championship - now trying to compete domestically. We're not talking about even trying to be in Europe.
"Celtic are a football team that expect to be playing in Europe but the realism is, just surviving a group stage is progression, because they weren't getting progression - they were going out, they weren't even in the Europa League.
"If Celtic finish third and progress to the Europa League then that is [progression]. When they get there they will want to go further in the competition that they did before."
Celtic are on course to secure at least third place in Group B after defeating bottom-club Anderlecht away from home in September.
McInally insists the Scottish champions are showing signs of improvement in the Champions League, despite heavy defeats to Paris Saint-Germain and Bayern Munich this season.
"Celtic have already gone to Anderlecht and turned them over. I think you would take third place right now," McInally said.
"Brendan [Rodgers] is talking about respect - I think they are earning more respect in Europe. I don't think they are being disregarded as quickly as maybe they were three or four years ago."
Former Manchester City defender Joleon Lescott believes Celtic have the quality to progress to the latter stages of the Europa League, should they fail to make it out of their Champions League group.
"I don't think that they're going to want to get into the Europa League and not progress and not be serious contenders for that competition," said Lescott.
"With their stadium and their fans, they can be."