Celtic's clutch of promising youngsters prove their worth vs. Bayern Munich

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