GLASGOW, Scotland -- It can be a double-edged sword for Celtic to be playing against the likes of Bayern Munich in the Champions League.
The Scottish champions certainly need the competitive challenge -- Saturday's 1-1 draw at home to Kilmarnock was a record-equaling 62nd unbeaten game in domestic football -- and Celtic Park truly comes alive when European football's superpowers come to town.
But playing against the best also provides a showcase for Celtic's top players to prove they can cut it outside the less-demanding arena of the Scottish Premiership, and that, ultimately, leaves the club vulnerable to raids for Brendan Rodgers' leading lights from wealthier outfits south of the border in England.
It has been a well-worn path over the years. Historically, the likes of Kenny Dalglish, Charlie Nicholas and Brian McClair have left Celtic Park for the biggest clubs in England, even when Scottish football could compete with the best around, and the direction of travel has rarely been in a northerly direction.
But the success in recent years of the likes of Victor Wanyama, Fraser Forster and Virgil van Dijk having left Celtic for England -- they all took their first steps in the Premier League with Southampton -- ensures that almost every English top-flight club watches Celtic regularly in an effort to find and claim the next one to roll off the production line in the east end of Glasgow.
Prior to this Group B clash with Bayern, Celtic received requests from 17 Premier League clubs for passes for their scouts to attend the game. Those that took their seats will not have been disappointed by the quality on view in green and white against the German champions.
Some may have made the trip to Glasgow to check out the talent in Bayern's ranks, but they will all have left with the names of at least six Celtic players in their notebooks capable of performing in the Premier League. Kieran Tierney, James Forrest, Callum McGregor, Moussa Dembele, Stuart Armstrong and Dedryck Boyata all showed their capability of performing at a high level against Bayern, with Tierney and Forrest, in particular, outstanding against Jupp Heynckes' men.
Tierney is the jewel in Celtic's crown, with the 20-year-old left-back signing a new six-year contract just 24 hours before this game. But the Scotland international performed with such poise and confidence against Arjen Robben and Kingsley Coman that it is impossible to imagine that he will not be snapped up by one of the Premier League's giants within the next 18 months.
Tierney was equally comfortable either defending or providing width in attacking positions, and he is undoubtedly a star in the making.
"Kieran Tierney against Robben tonight," Rodgers said after the game. "At 20 years of age, what a performance at that level."
Forrest, at 26, is arguably in his peak years and perhaps ripe for a move to England. His high-energy game from wide in midfield troubled Bayern all night, and it was his pass to McGregor that cut open the Bayern defence for Celtic's equaliser.
"James plays that role very well," Rodgers said. "He is one of the best wide players in terms of protecting the ball, but you can see his ability for the goal, which was a sensational pass."
Like Forrest, Armstrong is now at an age, 25, when English clubs will be prepared to take a chance on him. The deep-lying midfielder has been watched regularly by Southampton and Swansea, and his powerful performance against Bayern was clearly a tick in the right box for those clubs keen to bolster their squads in January.
Dembele, the 21-year-old French forward, troubled Bayern with his pace and movement, as he did when he did so well in the 3-3 draw against Manchester City last season, while Boyata displayed maturity and a reading of the game that a lack of minutes denied him the chance to develop during his time with City. The Belgian, now 26, took a chance on his career by moving to Celtic in 2015, but he has become a better player since heading to Glasgow.
With Celtic on course to finish third in Group B, however, and claim a place in the Europa League after Christmas, they will be in no rush to weaken their squad if wealthy English clubs come calling in January. Tierney will be the most difficult to keep, despite his new six-year contract, but the Isle of Man-born youngster has made it clear that he is in no rush to leave Celtic just yet.
So Rodgers might just be able to keep his team together until the end of a season that is likely to bring a seventh successive Scottish title.
If the Premier League raids begin next summer, it will be a tribute to the team Rodgers has built at Celtic, but also an unwanted side effect of performing in the Champions League. Celtic cannot live without these Champions League nights, though, so they simply have to cope with the downside that they bring.