Steven Gerrard admits Slavia Prague gained his instant respect with their shock win over Brendan Rodgers' Leicester.
The Ibrox boss has set his team the target of reaching the last eight of the Europa League, but to do that they must overcome Jindrich Trpisovsky's team.
Like Gerrard's newly crowed Scottish champions, the Czech outfit have yet to lose a domestic league match this season.
But the feat that really made the Gers manager sit up and take notice was their 2-0 win over his former Liverpool manager and one-time Old Firm sparring partner Rodgers' Foxes side at the King Power last month.
It was that result which set up their showdown with Rangers and Gerrard knows his side cannot afford a hangover from their title celebrations.
He said: "I think Slavia's performance over both legs against Leicester was extremely strong.
"Leicester are very good team with a good coach who so far have had a very good season.
"So instantly it made you well aware of the size of the challenge we're going to face.
"This is a team who is going extremely well domestically.
"We have major respect for the opposition, for the players, for the coach.
"As far as we're concerned we know we have to be at our maximum to get this job done.
"We will tell the players that they need to be ready and they need to be at their very best to complete this challenge because Slavia are a very good team, a very efficient team.
"They are really strong and powerful and can run a lot. They can also play from a technical point of view. We are well aware of the size of this challenge. We have to be at our very best to complete it.
"I want our players to go into the next two games with confidence and belief.
"But also with respect because this challenge is big. Anyone you face in the last 16 of a major tournament in Europe is going to be difficult.
"But I still have belief that if we can find two really strong performances it gives us a good chance of getting through.
"So it's a really fascinating set of fixtures coming up."
Striker Kemar Roofe returns to Gerrard's squad ,but the Ibrox boss revealed he has chosen to wrap midfielder Ryan Jack in cotton wool as he recovers from a calf injury.
Gerrard, who will also be without injured skipper James Tavernier, said: "Kemar will train this morning. He will be back in the group and will travel with us over to the Czech Republic and is available.
"Jacko, if I wanted him to be ready he could be. But I've decided to just hold back on him.
"He'll be available for the second leg, but I don't think it's right to push Ryan.
"He has had a bit of a different injury this time. Last time we probably pushed it a little bit too quick.
"I have decided, rather than the medical team, to just hold fire on that. It's a difficult decision but I think it's the right one in the big picture."
