Neil Lennon admitted his anguish over stricken Jackie McNamara as the former Celtic star fights for his life, the Daily Record reports.
The 46-year-old Hoops legend remains in a "critical but stable" condition after undergoing emergency surgery for a bleed on his brain.
McNamara collapsed near his home in York over the weekend and remains in intensive care at Hull Royal Infirmary.
The news of his former team-mate's illness hit Lennon hard.
He said: "I am lost for words, I don't know what to say.
"I spoke to him on Tuesday so I am devastated by the news and hoping he pulls through.
"People have been keeping me abreast of things. He is a strong guy, a great guy and a fit boy for someone of his age.
"He has been fit all his life so I am hoping and praying he comes through OK."
Earlier on Tuesday, The hospital confirmed McNamara's admission on Sunday night and released an update on his condition.
A spokeswoman said: "We can confirm Jackie McNamara was admitted to Hull Royal Infirmary on Sunday night and is currently being cared for in our Intensive Care Unit.
"He remains in a critical but stable condition. We are supporting both Jackie and his family, who request their privacy to be respected at this time."
On Monday night, McNamara's daughter issued a message via her father's official Twitter account, thanking fans from across the world of football for their support.
Several of McNamara's former team-mates and opponents, including Henrik Larsson and Ally McCoist, have sent their best wishes over the past 24 hours.
The tweet read: "This is Jackie’s daughter. Thank you for all your kind words and support.
"My dad is getting the best care possible, as you can all understand this is difficult for us as a family and request privacy at this time."
