Chelsea midfielder Cesc Fabregas believes Premier League clubs will struggle to sign players after the UK voted to leave the European Union.
The former Arsenal captain, currently playing for Spain at Euro 2016, expressed surprise and disappointment at the result of the referendum.
Fabregas joined Arsenal as a teenager from Barcelona only thanks to an exemption for European Economic Area (EEA) based players from Fifa's limit on international transfers for players aged 18 and over.
Non-EU players are currently only eligible for work permit to play in England if they've performed in a set number of games for their country in the two years prior to signing.
Fabregas believes the potential for European players to be subject to the same restrictions and the weakening of the pound could curb Premier League transfer activity.
"It's a very disappointing decision and I think very negative for many people," Fabregas told Italian newspaper La Gazzetta dello Sport on Friday.
"Personally I see it as a mistake. I didn't expect it, as I went to bed optimistic and woke up to this news."
"I think it's damaging for the Premier League. It'll be harder to sign players, the salaries will change if the pound gets close to the euro.
"It's a decision that will create many complications not just in football, but the daily lives and future of all people."
His comments echo those of Italy defender Giorgio Chiellini who is concerned that a Brexit could trigger similar movements across Europe.
Yesterday we went to sleep thinking that Britain would remain in the EU," said Chiellini. "Unfortunately that didn't happen, and I think the biggest concern is the domino effect that this choice could cause.
"I don't think it'll change the economy, the only concern is a referendum in other states. I'm sorry that, having worked hard to create Europe, this vote is a symbol of the discontent felt across Europe.
"We should come together, and look for a political solution for these problems...When there's discontent you vote for change, even without definitive plans and I think that's what has happened in England.
"I've read so many things. It happened in such a short time and there's sorrow for Britain's exit from the European Union."
When asked on his opinion on the historic vote on Friday, England striker Harry Kane said: "I woke up and saw the news. I don't think the lads are too focused on it. I don't think any of us know too much about it."