Swansea City chief executive Julian Winter says the club's American owners will invest more into the Championship club this year.

Winter says money is available to new head coach Russell Martin to bolster resources in the transfer window.

At his official unveiling, Martin admitted the squad was "a bit thin", although he made his first signing on Friday in midfielder Jamie Paterson.

"We are already on with two or three things," Winter said.

"You will get a better feeling when we get to the end of the window and what we have done between now and then."

Despite captain Matt Grimes, 26, who is entering the last year of his contract, being linked with a move to Fulham, Winter insisted summer strengthening was not dependant on selling players.

"The reality of it is we don't have to sell anyone unless the club gets an offer it thinks is suitable," said Winter, adding the club had not received "anything formal" in an offer for Grimes..

"Do we get an offer which is suitable? I don't know, I really don't know. We have not got one at this point, so who is to say what happens in the next three weeks."

Wales defender Connor Roberts is another player entering the last year of his Swans deal and has been touted for a move, but the 25-year-old is currently sidelined with a groin injury sustained at Euro 2020.

"Once we get through this window the discussions around players who have one year left on their contract becomes different," said Winter.

Swansea have cut costs since relegation from the Premier League in 2018, including selling key players such as Dan James, Oli McBurnie and Joe Rodon during that time.

In August 2020, the Swans received "significant investment" by way of a convertible loan from Oregon-based businessman Jake Silverstein.

Silverstein, who also has a stake in MLS side Houston Dynamo, subsequently joined the club's board as a director, alongside Jason Levien and Steve Kaplan, who matched his financial input.

Some Swans fans have bemoaned the perceived lack of investment from Levien, Kaplan and their fellow investors since they arrived in 2016.

But Winter said: "They invested last year, I think that was well publicised and they will have to invest again this year, so that topic has changed.

"They may not have done in the first three and a half years but they have done and will do again."

Martin's arrival as head coach last weekend ended what Winter described as a "challenging" summer following the departure of Steve Cooper as head coach.

Winter refused to elaborate on what led to the mutually agreed exit of Cooper, or on the situation with Queens Park Rangers assistant John Eustace - who turned down Swansea before Martin arrived from MK Dons.

"Now is not the time to go into the detail of all of that, because it is not fair on the people involved," Winter said.

"There will be a time when we can reflect on it a little bit more. The fact is it [Cooper's departure] was a mutual termination and we move on."

But Winter confirmed the US-based owners had the final say in the appointment of Martin.

"Their belief - and my belief as well - is that appointing someone like Russell Martin gives us a better chance of being competitive, creating that football identity the fans really want to see," he said.

"If all that comes together in a really constructive and positive way we will start to compete on the field. Where that takes us, let us get excited about that when it happens."