Atlético Madrid cannot provide a timeline for defender Robin Le Normand's return from a traumatic brain injury, manager Diego Simeone said on Saturday.

"We still don't have a clear idea about his return. The important thing is that he comes back well. That's the only thing we care about," Simeone told reporters on Saturday at a news conference ahead of his side's visit to Real Betis in LaLiga.

The 27-year-old player collided with Real Madrid's Aurélien Tchouaméni late in their 1-1 draw on Sept. 29, and needed medical attention on the pitch.

Le Normand suffered a traumatic brain injury (TBI) with subdural haematoma, the club confirmed earlier this month. He had made eight appearance since joining from Real Sociedad in the close season after winning the Euros with Spain.

"Once he is healthy, he can start anew with us like he has just arrived having rested after winning the European Championship," Simeone said.

Atlético have played four games across all competitions since Le Normand was sidelined, losing twice, winning once and drawing once, while conceding nine goals.

Asked about the team's poor defence following their 4-0 loss at Benfica and 3-1 home loss to Lille in the Champions League, Simeone said it came down to decisiveness.

"Both defence and offence prowess make you better ... but the reality is decisiveness in the areas and the team that is better in those situations will always be the one closer to winning," he said.

Sunday's opponents Betis, who are seventh in LaLiga, have lost only once in their five home matches this season, earning 10 of their 15 points from home fixtures.

Simeone's side are third in LaLiga with 20 points, four behind second-placed Real and seven behind leaders Barcelona.

Asked if he would be following Atleti's rivals Real and Barcelona in the Clásico later on Saturday, Simeone said, "My thoughts are irrelevant; what matters is giving value and importance to the game we have to play tomorrow.

"We have a difficult, tough match against a Betis side that plays better each time."

Atletico have decided not to sell tickets to some of their supporters for five away games in all competitions -- including their LaLiga games at Betis and Mallorca -- after sanctions from UEFA and the Spanish football federation (RFEF).