Spaniard Lopez was brought in to replace Carlos Queiroz as national coach in December, only a little over a month before the Asian Cup began, and had been in charge at Qatari club side Al-Wakrah until then.
Lopez said Uzbekistan posed the biggest challenge for the hosts so far but underlined Qatar's track record at the tournament, where they have reached the last eight by winning all their games and conceding only one goal.
"I know the players very well since I've been in the Qatari league for six years, I've watched them play in the league. They understand and accept instructions, we're in great harmony," Lopez told reporters ahead of Saturday's game.
"We have very talented players and we have fast players, probably the fastest. It will be a physical game, we have had enough time to recover," he said.
"The team has prepared very well. I also thought of rotatiIng the squad, we were smart in using the little time available to play everyone."
Lopez described Uzbekistan as the "strongest team" Qatar will have faced so far.
"I've seen some Uzbekistan players in the Asian Champions League. I've seen the quality of some of the players," he said.
"Qatar's last game against Uzbekistan was in 2018. Everything has changed since then - the team and the coach. I won't speak about the weaknesses of the team, otherwise, I would be revealing our plan. We will focus on ourselves."
Uzbekistan coach Srecko Katanec lost to Qatar in the 2019 Asian Cup when he was in charge of Iraq. He said his team would go into the match with "nothing to lose" at the 68,895-capacity Al Bayt Stadium, where home fans are expected in large numbers.
"My job is to prepare the team (the) best I can. We've been together for two-and-a-half years. I'm confident the players know how to play Qatar. We have some qualities that they have to be worried about," he said.
"When we started the tournament, I said we'd go game by game, analyse them well and prepare the team the best I can. Till now we've done well, but we will try to do our best tomorrow."
