Atletico Madrid have to be fully focused to emerge victorious in the second leg of their Champions League Round-of-16 tie against Inter Milan on Wednesday, coach Diego Simeone said.

Atletico, coming off a shock 2-0 defeat by relegation-threatened Cadiz in the La Liga on Saturday, will be hoping to turn around the 1-0 loss they had suffered last month in Milan.

Inter dominated the first leg and the home side’s solid defence prevented Atletico from any attempts on target.

“I understand everything that is happening to us,” Simeone told a press conference on Tuesday. “Until the home game against Athletic Bilbao we had a very good season, competing, (while) in the last few games the team did not maintain the level it had been playing at and we hope to continue to grow from the lessons we have learned.

“(Against Inter) it’s a game that requires a very high level of concentration and whoever has it, will win.”

Forward Antoine Griezmann, who sprained his ankle during the reverse fixture and had to be substituted late in the game, will be an important boost for the 2014 and 2016 finalists.

“His return to the team gives us more solutions and more possibilities, both tactically and as far as the game is concerned,” Simeone said. “Let’s hope he has the game he wants to play.”

Defender Axel Witsel said the Frenchman makes a huge difference when he plays.

“Grizzie gives the team a lot of strength and when he’s not there it’s different. He is an important player for us and we are very happy that he is back,” Witsel said.

Injured midfielder Thomas Lemar and defender Jose Gimenez were the only players missing from the team’s last training session ahead of the Inter game.

Injury woes

Inter Milan forward Marko Arnautović faces another month on the sidelines because of injury while teammate Carlos Augusto will also miss Wednesday’s match.

Both players had to come off in Inter’s 1-0 win at Bologna on Saturday after sustaining injuries. “The Austrian (Arnautović) has suffered a muscle strain in the right thigh, while the Brazilian winger has a calf strain in the right leg,” the club said in a statement.

Seeding system

The revamped Champions League will feature a tennis-style seeding system for the last-16 knockout phase, Uefa said on Tuesday. A semi-automated draw will also replace the manual draw.

Next season’s competition will expand from 32 to 36 clubs with the current six groups of four replaced by a single group in which teams face eight games against different opponents. The top eight will qualify for the last 16 while those finishing ninth to 24th face a playoff round to determine the other eight.