The Fir Park side were embarrassingly beaten 3-2 in extra time by part-time Icelandic minnows Stjarnan as they extended their winless European run to 10 games.
Veteran midfielder Lasley had what is surely the unique 'distinction' of conceding three penalties over the two legs - all of which were converted by the Fir Park side's opponents.
Stjarnan's winner came deep into extra-time and it will cost the cash-strapped Lanarkshire side £350,000 in UEFA prize money and the bumper gate they would have looked forward to had they played Lech Poznan, with the Poles having already informed Motherwell they would have been looking for around 4000 tickets for the tie in Scotland.
But far from hiding, the captain admitted after the game that his side should have beaten their tiny Icelandic hosts, after blowing a two-goal lead at Fir Park and twice going ahead in Iceland. Lasley is well aware that elimination in the competition could cost his side in the long run.
He said: "I've no doubts going out will mean there's less money to spend. If we'd gone through we'd have a good couple of ties, decent crowds, possibility of some TV money and that could maybe allow us to bring in an extra player.
"I know behind the scenes how much it means to the club going forward. So it's disappointing in every aspect from top to bottom. It was a poor night. Over the past few years we've had more good days than bad and this is one of the bad ones.
"You always try and enhance the squad, the manager has a track record of doing that fantastically. Financial constraints will dictate how much we can do, but 99% of the lads are in the team that finished second last season so there's still something in that dressing room that shouldn't be overlooked.
"We had it in our grasp at certain points in the game. We were the seeded team and the favourites so from our point of view, we feel as though we were the better side. But the scoreline doesn't lie and we've got to take it on the chin however hard it is at the moment. We have to move on but it's pretty raw at the moment.
"European football has taught us over the years that when you're in winning positions you consolidate that, and not leave yourself open because you will get punished. At 2-1 we felt very comfortable in the game, but we've given them a great lift and let them back into the game. Even in extra-time we had chances to go in front again. To go in front as often as we did and let it slip, we only have ourselves to blame."
Lasley endured a personal nightmare after his penalty disasters, but although he wasn't happy at the decision to award another spot kick against him in Reykjavik, he will not use that as an excuse.
Now, the Motherwell captain is just desperate for the new SPFL Premiership season to start. "We felt certain decisions went against us, but it's not about that, we should've been good enough to win the tie and we've not done it," he said.
"I couldn't believe the penalty. I don't want to talk about the ref, but from our point of view it was pretty poor. It's not a nice feeling, you want to contribute to the team in a positive way and it hasn't quite worked out that way for me.
"But I'm old enough and hopefully wise enough to bounce back from it on a personal level and contribute to the team in the course of the season. That's my job and the team's more important than me and how I'm feeling.
"It will hurt for a few days for everybody around the club. On the whole we've managed to come through and bounce back in our league form. We've still a lot of targets this year, but it hurts.
"We always get asked if we can punch above our weight again. It gets harder every year, you see the money going into Aberdeen and Dundee United, but we don't sit and moan about it, we make the best of what we've got.
"We'll make up with what we lack in finance in spirit and being a good team. It's hard to stand and talk about it just now but for a club of our size we've had a real consistent time.
"But in football you can't stand still or look back and we've definitely taken a backward step in Iceland."