The Dons limped into the second qualifying round despite going down to a 1-0 second-leg defeat against Luxembourg minnows Fola Esch a fortnight ago.
Thankfully for Derek McInnes' men, their 3-1 triumph at Pittodrie a week earlier was enough to see them through to a clash with Latvian outfit Ventspils.
A 3-0 home win has now given the Scots a comfortable cushion as they prepare for Thursday's return leg, but McLean knows their Baltic hosts will come out quick looking to put them under pressure once more.
But having survived a scare against Fola, McLean insists Aberdeen have learned their lesson.
"I can assure you there won't be a repeat," said the midfielder. "We have spoken about the Fola Esch game at length. It was early in the season, only a couple of games in.
"The result can't be excused but we know we have a job to do over here and we need to put things right with the travelling fans. It will be a tough game but we're in a good position and hopefully we can stay there.
"We know what to expect. In Luxembourg, Fola came at us early and we will need to weather a bit of a storm again this time.
"If you watch the first leg you can see Ventspils like to get around their big striker, who is probably their main player. We need to try and stop that threat by cutting them off at source.
"We know their threat but we also know how good we are. We have got a lot of quality in this squad and we're confident we can go there and score. If we do that, it gives them a mountain to climb."
Source: BT Sport