Telfer, who won 22 caps for Scotland as a player before coaching the national side to a Grand Slam in 1984, is betting on Glasgow doing all they can to secure a home semi-final, with Edinburgh falling just short and missing out on the Play-Offs all together.
Both sides have been at the heart of the race for the inaugural Magners League semi-finals throughout the season but only Glasgow have already guaranteed their place in the final four.
The Warriors are aware that victory over the Scarlets could result in a home semi but Edinburgh go into their Round 18 clash with leaders Leinster knowing that even a shock bonus-point win may not be enough to claim fourth spot.
"In another twist in the Magners League playoffs saga, the defeats of Munster and Leinster (in the Heineken Cup) is not particularly good news for the Scottish pro teams," Telfer told STV.
"The result in Toulouse was of particular importance to Edinburgh who are fighting for the fourth playoff spot with Cardiff Blues and Munster. They play Leinster who themselves need a win to guarantee home advantage in the semi-finals.
"Edinburgh must win with a bonus point to progress as Munster are already four points ahead of them and have a superior points difference. I can't see Edinburgh doing it, if their recent form is anything to go by.
"Cardiff Blues play Munster at home on Sunday and, as they have already won through to the Amlin Challenge Cup final, may just rest some of their top players. That would help the Irish province who just need a losing bonus point to qualify.
"Glasgow have a far more straightforward scenario. They have already qualified and have a chance of second place if they beat Scarlets, and gain a try bonus point as well. Their form in Wales in recent league matches has been good and I'm confident they can get the five points."
Although Telfer's pessimism regarding Edinburgh's cause is somewhat understandable given the size of the task facing them at the RDS, he isn't quite right to say that Munster only need a losing bonus point in Cardiff to make it through in fourth place.
Even if the reigning champions do pick up a single point against the Blues, both the Blues or Edinburgh could still qualify if they can overtake Munster on points difference.
Munster's difference between points scored currently sits at 38, with the Blues on 33 and Edinburgh a further 30 points back on plus three.
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