The Saudi Pro League continues to edge closer to competing with Europe's elite competitions as lucrative contracts entice players who "work for money".

That was the message from Portuguese winger Fabio Martins, who switched Braga for Saudi Arabian football and plays his football for top-tier side Al Khaleej.

Martins' compatriot Cristiano Ronaldo – as well as Neymar, Karim Benzema, Sadio Mane, Jordan Henderson and N'Golo Kante – all followed suit with moves from Europe to the Middle East and have reaped financial rewards.

The ethics of those transfers, in a country where same-sex marriage is prohibited alongside questions over its human-rights record, have been scrutinised – but Martins understands why Europe's top talent are moving ashore.

Martins, a former Portugal youth international, told Stats Perform at the Thinking Football Summit: "I believe that all of us, players or not, work for money.

"You are a journalist and you work for money and I'm sure that if some brand or some [newspaper] came to you to give you more money to change your job, you will change it because all of us want money.

"I believe that people are free to choose what they want for their life. I'm not critical because I'm here too for sure.

"When I arrived here I came 80 per cent because of the money because they pay me much more than in Portugal, so it's a thing that I don't understand people judging the others because of his choices.

"We have freedom to choose what we want what we want for our life, and what we want for our career."

Real Madrid midfielder Toni Kroos labelled Gabri Veiga's move to Al-Ahli as "embarrassing" after the promising Celta Vigo youngster was tempted into a Saudi Arabia move.

But Martins insists players, whether at the end of their career or the start, cannot refuse the proposals on offer in case they do not come to fruition again.

"I understand Kroos because maybe he saw a lot of potential in Veiga, and he was kind of young [but at 21] if he gets one proposal like this, you don't know if in two, three or four years [that another proposal like this will come]," Martins added.

"I said a lot of times to the people beside me, around me, that in Portugal we say [the train does not stop in the same place twice].

"You get the proposal. You don't know if the proposal will come again with these numbers, with this money, so we have a time to say yes or say no and we have to make choices.

"I believe that all the players that are here are happy.

"The people around football and out of football, they all change places, they change jobs too because of the money, so I don't understand this judgement."

A plethora of Europe's top talent from the Premier League, La Liga and Bundesliga have joined the Saudi Pro League, as the Middle East look to close the gap on football's top competitions.

Martins believes the next step for the development of the Saudi Arabian top tier will come from investing in management and well-known head coaches.

He continued: "I believe the league still has a lot of potential to grow but without a doubt is getting closer to these big leagues.

"However, I think it's not in the same step yet.

"But with these kind of players arriving I think the one thing that I would invest in, if it was me with the money, is about the professionalism in the management too.

"I would bring some foreign managers to the clubs because with this level of investment, if you have good management too and not only good players, the league will grow much faster.

"With these and with a lot of sponsors and marketing, the league will grow and in three, four or five years, I think that the Saudi league will be in the level of the Premier League."