Carlos Carvalhal says he and his coaching staff "changed almost everything" about their approach to football after suffering relegation from the Premier League with Swansea City in 2018.

Carvalhal made a name for himself in the English game by leading Sheffield Wednesday to the Championship play-off final in 2016, where they were beaten by Hull City.

Wednesday were then beaten in the semi-finals after finishing fourth under Carvalhal in 2016-17. That remains their highest second-tier finish since 1990-91, when they were promoted in third.

However, Carvalhal left the Owls for Swansea City in December 2017, only winning eight of 25 games in south Wales and overseeing their relegation from the Premier League the following May.

Carvalhal has since enjoyed something of a renaissance with the likes of Rio Ave and Braga, before moving to Spain to keep Celta Vigo up with a final-day victory over Barcelona last season. 

The Portuguese coach is proud of his achievements since leaving English football, claiming his stint at Swansea provoked a change in his approach to the game.

"After England, we were at Sheffield Wednesday for two and half years and half a year at Swansea, then we stopped for one season," Carvalhal told Stats Perform at the Thinking Football Summit.

"We decided to stop and reflect on the things that we did and the things that we wanted to do in the future. We changed almost everything. In this moment, we saw football in a different way. 

"We are not basing it on the system [anymore], we are basing it on spaces and creating spaces. It's the way that we look at football, completely differently, like a chess player looking at the table.

"The results were fantastic, I can tell you. 

"We took a big risk to go to Rio Ave. Rio Ave is a medium club in Portugal. We were in the Premier League, and nobody from the Premier League goes to Rio Ave. But we decided to go there because it's a calm club, there were some good players, we could put our ideas on the pitch. 

"The reality was that we achieved Europa League [qualification]. Braga the same, we continued improving, in Celta Vigo we improved and we have stopped now to refresh a little again.

"I know €14 million was raised in Rio Ave with the players that we developed, which is very good for the club. Almost €100 million at Braga, and now in Celta Vigo with Gabri Veiga and Javi Galan probably about €50 million. So we are improving players.

"It's something that of course we are very proud of and something that we want to do in the future in the next challenge."

Carvalhal oversaw Rio Ave's best points return in their Primeira Liga history in 2019-20 (55 points), before leading Braga to their third – and most recent – Taca de Portugal one year later.

The 57-year-old has been out of work since leaving Celta in June, but he is ready to get back into the game and believes taking regular breaks is crucial to stay fresh.

"The gaps, I need to rest for my mental health, which I care about. Usually, you never see me have problems with other coaches, with referees and so on, because of these kinds of things.

"I decided [to move] because we did very well [at Braga]. We did the best the club has done in its history. In two seasons, we won the cup and we reached three finals. 

"We achieved the quarter-final of the Europa League, 17 players from the academy played in the first team. At Celta Vigo, we arrived at the club in a very difficult position. We finished in 13th. 

"There's a lot of pressure. So I spoke with my staff, I said I need to stop for three or four months and after, we go back to the market. So at this moment, we are on the market again. 

"We are not under pressure, it's not about money. We can't say that we don't ever go for the money because we never know what will happen tomorrow, but I would prefer to go because of passion and football. Let's see what happens."

Carlos Carvalhal has refused to rule out a move to the Saudi Pro League, also expressing pride for his role in Gabri Veiga's development after the young midfielder joined Al-Ahli.

Carvalhal has been out of work since leaving Celta Vigo in June, having kept the club in La Liga courtesy of a dramatic final-day win over Barcelona.

Prior to his stint in Spain, Carvalhal led Rio Ave to a club-record tally of 55 points in Portugal's Primeira Liga in 2019-20, before moving to Braga and winning the Taca de Portugal the following season. 

The Portuguese coach is no stranger to the Middle East, having managed UAE Pro League outfit Al Wahda in 2022, and he would not necessarily be against a move to Saudi Arabia.

Saudi Arabian clubs have spent heavily in the transfer market this year, acquiring the likes of Karim Benzema and Neymar after the country's Public Investment Fund took control of four of the league's biggest clubs.

Though many have expressed concern about the financial power of Saudi clubs and the potential for the league to act as a "sportswashing" vehicle for the state, Carvalhal would be open to a move if presented with an attractive project. 

"We never know. We never know. I have said that if the project is structured, let's see," Carvalhal told Stats Perform at the Thinking Football Summit when asked if he would manage in the league.

"It has not been a long time. If the project is to buy good players, with good coaches and also to develop youth football, if there are these kinds of projects in the future, I believe they can do something important.

"I remember China six years ago or seven years ago, they bet with very good coaches, very good players and after one moment they decided, 'no, we don't want this anymore, we are spending too much money', and they finished. 

"It's over to everybody [in Saudi Arabia], let's see if this is consistent, if it will be here for 15 or 20 years. 

"It is very welcome what they are doing – if it's something circumstantial. It's something that we don't know [yet]. "

Carvalhal's Celta side was built largely around the talents of Veiga, who scored twice as they upset Barcelona to clinch survival back in June.

Veiga was linked with Serie A champions Napoli before opting to join Al-Ahli, who also signed Riyad Mahrez, Roberto Firmino, Edouard Mendy, Allan Saint-Maximin and Franck Kessie in the recent window.

Carvalhal is proud to have played a role in Veiga's development, highlighting the way his move brought much-needed funds to Celta.

"Gabri Veiga for Celta Vigo in the B team was like a striker, then we decided to put him in the second midfielder [role] because the way that he plays there, he can score goals and give assists," he said.

"It was a big challenge for him because he started as a striker and after with us, we played with two midfielders, and he was one of the midfielders. 

"He has improved to another level in this kind of position, with the goals and breaking lines. 

"Of course, when he finished the season and we saw that big clubs wanted him, he moved to Saudi Arabia as an option.

"Big money came into the club, of course. We are very proud and very satisfied about everything."

Celta have four points from five matches under Carvalhal's successor Rafael Benitez, who has become the first coach in the club's history to lose his first three home league games at the helm.