Jon thinks that if Glasgow can keep up the standard they set in the second half of the 43-17 loss to Toulouse in France, they can still wriggle their way into the knock-out stages.
Jon said: "We feel a different kind of disappointment to the one we felt after the Northampton match last weekend - but the frustration is equally acute.
"We showed after the interval what we are really capable of at this level against one of the greatest clubs in the world.
"It was just a pity that we had lost our momentum in the first half when we gave the ball away too easily.
"We definitely don't regard ourselves as being out of the competition. We have back-to-back games coming up against Llanelli Scarlets and we have beaten them twice in a season in the past.
"Two good wins would keep us in the picture."