Kepa replaced Chelsea No.1, Edouard Mendy. It was just over a minute before Kepa saved two penalties to help the Blues to a 6-5 win in a penalty shootout. Mendy’s body language as he was being replaced suggested that the move had been planned. Tuchel, who spoke after the game, said that the decision was taken before Chelsea's FA Cup tie, which is Barnsley's February match. This was Tuchel’s first cup match in charge of the club. Tuchel was full-lauded for both goalkeepers by the European champions. They had made a winning start into competitive action. Tuchel said, BT Sport: "It wasn't spontaneous." "So, we had some stats, we were well-prepared, that Kepa was the best in percentage saving penalties. "The analysis team and the goalkeeping coaches showed me the data and then we spoke with players. This can happen when you play in a knockout, and since then they are aware. "It's wonderful how Eddy accepts." It's amazing to see how much this talk took place before the Barnsley cup final. Since then, they have known. "Of course, we needed to do what's best for the group. It was necessary. It worked. "There is evidence that Kepa does better at this discipline. These guys are truly team players. Eddy and Kepa have great goalkeepers. Eddy doesn't take pride in not taking the field off and is happy to play for the team. It's great. Kepa also explained to BT Sport afterward that it was not a typical scenario. We are so happy that we won. I believe that all the teams did a wonderful job and we received the medal. It isn't a normal situation. Because it can happen, I was prepared. I strive to be mentally as well as physically prepared." Mendy continued: "Officially, I am happy because it was a win. We work for it, for success. Since last year, I knew that Kepa would be there to pitch the team. He did this today, which I am extremely happy about. "It's teamwork. This is a team effort. Chelsea is the team that you play for. We did it together, we are happy. 'Mentally Good, Physically the Worst' Chelsea had taken an early lead through Hakim Ziyech after 27 minutes. Villarreal however improved and eventually scored their equalizer through Gerard Moreno, after 73 minutes. Tuchel admits Chelsea's shortcomings, but the team won overall. He said that it was difficult to complete 120 minutes of work out of less than nothing. "We were quite strong in the 30 and 35 minutes before we started to lose a few of our easy balls. "The second-half was too passive. Too many balls were lost. They even equalized. This is well deserved. However, after conceding our goal, we were once again very strong. "We invested I believe more in the 120 minutes, and we deserved a win." Tuchel's Premier League side hosts Crystal Palace at 3 pm Saturday. The claimed 120 minutes was not enough preparation. "Mentally [tonight] wasn't bad, but physically it was one of the worst things that could happen to Saturday afternoon." The victory helps us to recover, and we have now to be careful," he stated. Chelsea suffered one setback: Ziyech, the goalscorer, sustained a worrying shoulder injury and was forced to leave the game. Ziyech appeared on the sidelines for the second half wearing a sling. "If you dismiss a player in halftime, it can be serious. Unfortunately, he was a very decisive and important player for us during the last games. Analysis: Tuchel makes it right once again Sky Sports' Adam Bate: "It wasn’t easy for Chelsea. Villarreal could have won this. The Champions League champions found it difficult after a strong start. Tuchel continues his remarkable start at Stamford Bridge. He received the big call. "There was some humor when Kepa arrived on the pitch. It was the accepted wisdom that Mendy was the better goalkeeper and, therefore, would have been better placed to save penalties during the shootout. Tuchel doesn't believe in the accepted wisdom. He believes in logic and analysis. "The data indicated that Kepa is less likely to save spot-kicks than Mendy. He accepted it and knew that, while Chelsea would have criticized it, there was a method behind the decision. Tuchel's methods have worked for him in England.