By Martin Conaghan

Scott Brown joined Celtic from Hibernian for �4.4m

If friendlies are any measure of Celtic's strength, then the league champions should be worrying about their title defence.

Thus far, Gordon Strachan's men have failed to demonstrate a consistent approach to their pre-season build-up, suffering two 4-1 defeats against Young Boys of Berne and Newcastle United.

However, only a fool would hedge a title wager based on the outcome of such meaningless encounters.

As with last season, Celtic's poor performances in warm-up games will have little bearing on the outcome of the 2007-08 season.

For a start, the Glasgow side are currently the big net spenders in Scotland, having forked out almost as much on a single acquisition as the rest of the SPL teams have combined.

In attracting Hibernian's Scott Brown to Celtic Park, along with Motherwell's Scott McDonald - when both players had indicated an interest in joining Rangers - Celtic have sent out a clear message of financial strength to rival bidders.

Of course, money doesn't always buy success but it's difficult to argue with the quality Celtic have managed to attract during the summer transfer window.

Gordon Strachan has won four trophies since joining Celtic

And let's face it, it's been a long time since a team with no funds made a significant impact on Scottish football.

Last season's impressive run in the Champions League has contributed to a healthy balance sheet.

However, European competition will be second on the list of Strachan's main challenges this year; retaining the league championship title for a third successive season will be first.

The only time a third successive title triumph has been achieved in Scotland since 1946 is when Celtic notched up their record nine-in-a-row from 1965-1974, and when Rangers equalled the feat from 1988-1997.

Celtic will start as favourites, having sewn up their last two titles by Christmas and showing on several occasions last term a steely determination to come out on top even when not at their best.

But Mr Strachan will be keeping a cautious eye on the goings-on at Ibrox.

MYSPORT DEBATE Can Celtic win their third title in a row? MySport: Have your say

Rangers are a side filled with newfound confidence following the return of stalwart Walter Smith and, despite losing ground financially, they should present a significant threat to Celtic.

Strachan may not be the media's favourite interview candidate, but the popular myth that he is disliked by the Celtic support simply because his background is not rooted in the club's history is patent nonsense.

Averaging two trophies a season, Strachan is on course to equal Martin O'Neill's haul in a shorter time span and he has guided Celtic to the last 16 of the Champions League for the first time.

And his critics should know better; defeat or victory at St James' Park means absolutely nothing, unless a place in the next round of the Champions League is at stake.