Senator John McCain wished his followers a Merry Christmas before thanking Arizona Cardinals's Larry Fitzgerald for a letter he wrote offering prayers for his friend who has been battling brain cancer since July.

The senator, hospitalized for a viral infection before returning home, shared a photo of his family celebrating the holidays in a post on Twitter on Monday.

McCain, who did not participate in the tax-plan vote earlier this month, said: 'Merry Christmas & holiday blessings, from our family to yours!'

Senator John McCain, who has been battling brain cancer, shared a photo of his family celebrating the holidays in a post on Twitter on Monday

McCain, who did not participate in the tax-plan vote earlier this month, said: 'Merry Christmas & holiday blessings, from our family to yours!'

The post included two photos: one McCain seated with wife Cindy, daughter Meghan and son-in-law Ben Domenech in formal attire and another of him wearing casual white sweats with the rest of his family. He still wears the brace from when he injured his Achilles heel.

The 81-year-old would soon make a follow up post in response to an open letter Fitzgerald wrote for Sports Illustrated sending him prayers as he continued to fight cancer.

'Thank you @LarryFitzgerald, I'm deeply touched,' added McCain.

'Thanks for all you do to give back to #Arizona & our nation. Merry Christmas!'

Fitzgerald, who has played with the Cardinals since 2004, took to Sports Illustrated to wish people a Merry Christmas but also tell of his admiration of McCain.

The 81-year-old would soon make a follow up post in response to an open letter Fitzgerald wrote for Sports Illustrated sending him prayers as he continued to fight cancer

'Merry Christmas, everyone. As we enjoy this special day and celebrate the holidays with friends and family, I'll be thinking about someone who has become very important to me: Arizona Senator John McCain,' said the wide receiver, who has developed a friendship with McCain over the years.

Fitzgerald would continue by explaining how he thinks of 'giving' when he thinks of John McCain and shared of a 2013 visit he made to Vietnam to tour the places where the senator was held prisoner during the Vietnam War.

'The sacrifices John McCain has made for our country, and especially the men and women he served with in the military, are incredible,' he said.

'As a prisoner of war in Vietnam he missed six Christmases with his family back home and suffered unbelievable hardship.'

'Merry Christmas, everyone. As we enjoy this special day and celebrate the holidays with friends and family, I'll be thinking about someone who has become very important to me: Arizona Senator John McCain,' said the wide receiver, who has developed a friendship with McCain over the years.

The NFL star then went on to mention how McCain could have came home four years sooner had he used his father's, John S McCain Jr, status as a 'high-ranking military commander.'

He added: 'However, he refused to be freed until all the men captured before him were released. That is true heroism and bravery.

'He gave so much in the service of his country, and that commitment to service continued as he was elected to Congress in the 1980s.'

Fitzgerald shared that while he wasn't a 'political guy', he was fascinated by the history surrounding the war.

McCain spent six Christmases in Vietnam as a Prisoner of War and for Fitzgerald, seeing the jail cell where the senator stayed was monumental.

'Senator John McCain again finds himself in a battle. This time it's with cancer, and the treatment he's undergoing is exhausting. I'll wish him a Merry Christmas today, and I pray he lives another 20 years,' Fitzgerald added

'I saw the very jail cell where he was held as a POW and I tried to imagine what it must have been like to be him. I took a photo of myself next to his flight suit, the suit he was wearing when he got shot down,' Fitzgerald said.

'So powerful. So meaningful. Those images will never leave my mind.'

McCain was diagnosed with a brain tumor in July and returned home to Arizona this month, avoiding the Senate vote for the finalized version of the GOP tax plan.

Fitzgerald sent a tweet of support once news reached that McCain was coming home to Arizona to celebrate the holidays with his family

'Senator John McCain again finds himself in a battle. This time it's with cancer, and the treatment he's undergoing is exhausting. I'll wish him a Merry Christmas today, and I pray he lives another 20 years,' Fitzgerald added.

'As soon as my boys are of age, I'll tell them stories about the quality of the man I've gotten to know. I'll tell them: Senator John McCain will be revered and respected for as long as the United States of America has a place in this world, and his legacy will outlive us all.

'My prayers are with you, my friend.'