SAN DIEGO – The twin brother of Paul Whelan, the American detained alongside basketball star Brittney Griner in Russia, says that he has hopes that his sibling will come home soon.

“It’s a cautious optimism, I think,” David Whelan told FOX 5 in a recent interview.

Last week, the U.S. State Department announced that officials are working on a deal to bring home Paul Whelan, who has already been detained for three years, as well as Griner.

“President Biden spoke to our sister a month ago and so that was really a huge confirmation that Paul is a priority for them. But for Secretary Blinken to take the extraordinary step to announce that they had made a concession to Russia, that gives us a lot of hope that perhaps it’s something that the Russians will want and will accept and then release Paul for it,” said David.

The White House has offered to exchange a convicted Russian arms trafficker for the release of Whelan and Griner.

Paul was arrested in 2018 for spying, a charge that he and his family vehemently deny. The American has spent more than 1,300 days in custody and is currently in a labor camp.

David told FOX 5’s Jason Sloss that he hasn’t talked with him, personally, but their parents get frequent phone calls.

“He was put in solitary for a month and that’s a terrible thing to experience. We sent him medicine and that’s stolen by guards. So there are ongoing sorts of petty abuses that happen,” David said. “He seems to be able to hold together his mental health and I think that’s due to his Marine Corps training. It’s his physical health we’re worried about.”

Griner is on trial facing drug charges. Her case made the news across the world after she was arrested at a Moscow airport in February.

Now, David says that he believes the national attention on Griner is helping his brother’s situation, also.

“Because she is in Russia as well, it’s very hard to not look at both of the cases together. Her celebrity has meant that a lot more people know about Paul’s case than did before. Her celebrity is also helping — there’s about 50 other Americans in the same boat around the world in Venezuela and China and Iran and so her celebrity is helping to put a spotlight on wrongful detentions, broadly,” said David.