League Cup: Tuchel Hails $93M Star Calling Him 'Big Part' After Chelsea's Win [Watch]

Thomas Tuchel hailed goalkeeper Kepa Arrizabalaga after Chelsea defeated Southampton on penalties to qualify for League Cup’s quarter-final on Tuesday.

Kai Havertz, who has been struggling to find form, opened the scoring at Stamford Bridge Tuesday, which was his second goal in three matches for Chelsea. A few minutes later, Southampton forward Che Adam netted an equalizer.

The scoreline remained 1-1 till the end before the result was decided via penalty shootout. Chelsea went on to clinch the Round of 16 tie after Reece James netted the winning goal from the spot-kick after Theo Walcott and Will Smallbone failed to hit the target for the Saints.

"He [Kepa] produces. He is full of confidence. He has this experience now with us, and he has done it again and again. Just because you win a penalty shoot-out, does not mean you will do it again. Full credit to him. It’s a special thing in football and we were again concentrated and calm. Kepa was a big part of that," Tuchel told Chelsea’s official website after the win against Southampton.

The Chelsea head coach also admitted that they had expected the Round of 16 game against Southampton to be "difficult."

"We were expecting it to be difficult. It was a nice match of football from both teams, a really tough match, and in the end, we are happy to win the penalty shoot-out. When you play Southampton you know what you get, intensity, high pressing, a team full of courage and speed. It’s their identity. You have to accept things get tough, and the challenges are constantly there. That’s why I am happy with the performance and the result," added Tuchel.

Tuchel also opened up on Chelsea’s last-minute changes ahead of the Round of 16 tie in the League Cup on Tuesday. As many as three players -- Cesar Azpilicueta, Ruben Loftus-Cheek and Andreas Christensen were forced to sit out due to various injuries.

"We hope Azpi is back for the weekend. He had a shoulder injury yesterday in training when he fell on it. It’s very painful but he’s Azpi and he’s a tough guy. Ruben felt after training some pain in his hip joint. Hopefully, we can handle it for Saturday. Andreas needed to recover from tooth surgery and he should be back in training on Thursday if there are no complications," said Tuchel in the same interview.

Chelsea are next headed to St. James’ Park to take on Newcastle United in the Premier League on Saturday. While Newcastle are in 19th place in the points table, the Blues are the current table-toppers, one point ahead of second-placed Liverpool FC.