THEY say that if you can handle the challenges of your Premier League debut, you’re already well on the way to carving out a successful football career. For Middlesbrough defender Tomas Kalas, however, that task was rather trickier than most.

While most first appearances come towards the end of a nondescript game when the pressure levels have dropped, Kalas’ maiden start for Chelsea came in the match that would ultimately decide the destination of last season’s league title. So no pressure there then.

With his side suffering a defensive injury crisis, Jose Mourinho pitched a 20-year-old Kalas into Chelsea’s starting line-up for last April’s trip to Anfield.

The game would come to be remembered for the Steven Gerrard slip that did so much to cost Liverpool the title, but for Kalas, the memories of a monumental afternoon are dominated by the tackles that helped secure Chelsea’s clean sheet, the shot that rattled off the Anfield crossbar and the full-time celebrations at a job well done.

With his new club, Middlesbrough, in the thick of the Championship promotion hunt, there will be some pressurised times ahead for the defensive loanee. But having survived the rigours of his top-flight debut eight months ago, he is confident of being able to take them in his stride.

“I made my debut at Anfield and we won,” said Kalas, who made an impressive Middlesbrough debut at right-back in last weekend’s goalless draw with Reading. “It doesn’t get much better than that.

“We might not have played really nice football, but we won 2-0 and I was glad that I could play my first game there. It wasn’t the easiest way to start my games in the Premier League, but it was a great place to start.

“It was funny in the dressing room before the game. Jose Mourinho was asking Mark Schwarzer, Ashley Cole and Frank Lampard who they played their first game against, and they were saying Barnsley and Doncaster and teams like that. He said, ‘Well, you will start against Liverpool’. It was nice to do that, especially because we beat them and didn’t concede a goal.”

Kalas made one more Chelsea appearance last season, starting the 2-1 win at Cardiff City on the final day of the campaign, and is among a clutch of players currently away from Stamford Bridge on loan deals in an attempt to speed up their development.

Born in Olomouc, in the Czech Republic, the 22-year-old started his career with his hometown club, Sigma, before signing for Chelsea as a 17-year-old in 2010.

The fact the Blues were willing to pay around £5.2m in order to secure his services as a teenager underlines how highly he was regarded in his formative years, and having spent half a season in Chelsea’s development squad, he was sent to Holland for two successful loan spells with Vitesse Arnhem.

“I was 17 when I left to join Chelsea, and it was a very big move at that age,” said Kalas. “I didn’t for one minute think that I would be playing for the first team when I was 17. The main reason I moved is because Chelsea have the very best in everything and I knew they could help me to get the ability to play at the highest possible level.

“I didn’t want to be playing junior football in Czech Republic all the time, and the move to Chelsea worked really well. In my first half year, I was playing for the second team and we won the league. I was training with the first team, so it was a really big step in my career.

“Then I went for two years to Vitesse Arnhem and was playing for 60 games in a row. I don’t think I would have been able to do that if I hadn’t had that half year at Chelsea.”

A loan move to the German side Cologne in the first half of the current campaign did not go as planned – Kalas did not make a single senior appearance for the Bundesliga side before Chelsea took him back to Stamford Bridge – but the early signs suggest his move to Middlesbrough will be much more fruitful.

It will be interesting to see whether he retains his place in the starting line-up once Damia Abella and Ryan Fredericks are fit, but for now, he will be a crucial part of Middlesbrough’s back four as they attempt to continue their promotion push in back-to-back home games against Huddersfield Town and Cardiff City.

“When you are standing on the floor in your career, and not flying in the air, you have to be honest and say you are not yet good enough to be playing for Chelsea every game,” he said. “You have to drop down a little bit and choose the team where you have a better chance of playing games and doing well.

“All the right-sided defenders are injured at the moment, but hopefully I can keep my place by doing well. Hopefully, the choice to go to the second league will help me. The best thing would be if I could stay here and help Middlesbrough get promotion to the Premier League.”