BARCELONA -- Marc-Andre ter Stegen said Barcelona can't dwell on the last week's mistakes as they look to end a three-game winless run when they face Tottenham in the Champions League on Wednesday.
Barca began the season with six straight wins in all competitions but have been beaten 2-1 by La Liga's bottom club Leganes and held at Camp Nou by Girona and Athletic Bilbao in the last 10 days.
"This is how football goes sometimes," Ter Stegen told ESPN FC. "There will be, like against Leganes, games we won't be happy with, but it's a long season and we need to get back to our strengths.
"We need to be focused on the next game. What happens in the past is difficult to change but we can learn from our mistakes and also what we did well -- and there are things we did amazing in the last couple of matches.
"We have a lot of upcoming games and we want to be in good shape. Everybody needs to be focused on what's next. I think we are doing [that]. Everyone is trying to do their best, making the team a bit better, and that's how we can have a good season."
This week's match at Wembley marks the start of a tough October for Barca, with fixtures against Valencia, Inter Milan, Sevilla and Real Madrid to follow.
One area for improvement for Ernesto Valverde's side is in defence, with Barca having already conceded eight goals in the league, more than nine other sides in Spain's top flight. And Lionel Messi admitted at the weekend that they have been too weak at the back.
On Wednesday, Barca will be tasked with keeping Harry Kane off the scoresheet in London, although Ter Stegen said it would be a mistake to focus solely on the England striker.
"We have played a few times against England with [Germany] and of course he is very good," he added. "But, let's be honest, they have a good squad. In the last few years, they have had amazing seasons in the Premier League. They've been very [consistent] at the level they're playing.
"It will be interesting. The atmosphere will be interesting for all of us. It's something different. It's a big game and everybody is looking forward to it."
Barca's La Liga triumph last season was their seventh in 10 years, while they won a fourth successive Copa del Rey trophy, but they've watched on in envy as Real Madrid have won the last three Champions Leagues.
In a bid to return to the top of Europe, they signed Arturo Vidal, Arthur Melo, Clement Lenglet and Malcom in the summer. However, Ter Stegen pinpointed Philippe Coutinho, who was cup-tied for the knockout rounds last year after signing from Liverpool in January, as the potential difference maker.
"I think it's good for us now that Coutinho is able to play in the Champions League," the goalkeeper said. "He gives us different options, of course, and in general we have players who can also be competitive at the highest level I think.
"We have an amazing squad and we always have done. During the last few years, we have always had an amazing squad. This year, we lost one player [Andres Iniesta], who I think is super important for the club, for the team, but, of course, we tried to get new signings. The club did what they thought was best for the team and I think they did well."
Barca have exited the Champions League at the quarterfinal stage in each of the last three years. Last season's loss to Roma, though, hurt the most as they surrendered a three-goal first leg advantage on their way out of the competition.
"In general we had a good situation last year," Ter Stegen said. "I mean, we won the league, we won the Copa del Rey, everyone expected more after winning the first leg against Roma, but we couldn't find the solution.
"This is how football goes sometimes. We didn't make a good match, we didn't really deserve it. They played a very good match. Maybe the 4-1 [in the first leg] was a fake result which was maybe higher than how the game was. It was much closer.
"But we have learned from our mistakes and hopefully we can avoid them this season and keep moving forward."
Barca beat PSV Eindhoven 4-0 in their opening Champions League game this season, while Tottenham conceded two late goals as they lost 2-1 to Inter.