Bob Odenkirk is in a "stable" condition after collapsing on the set of 'Better Call Saul'.
Bob Odenkirk is the titular star of the series, playing the con artist turned lawyer Saul Goodman.
The show is currently in production on its sixth and final series.
His representatives sited the reason for the collapse as a "heart-related incident."
They issued a statement reading: "We can confirm Bob is in stable condition after experiencing a heart-related incident.
"He and his family would like to express gratitude for the incredible doctors and nurses looking after him, as well as his cast, crew and producers who have stayed by his side.
"The Odenkirks would also like to thank everyone for the outpouring of well wishes and ask for their privacy at this time as Bob works on his recovery."
Legions of fans sent Bob Odenkirk well wishes, as did his former co-stars Bryan Cranston and David Cross.
'Arrested Development' star David Cross wrote on Twitter: "I will share what I know when I can but Bob is one of the strongest people I know both physically and spiritually. He WILL get through this."
He wrote: "Today I woke up to news that has made me anxious all morning.
"My friend, Bob Odenkirk collapsed last night on the set of Better Call Saul. He is in the hospital in Albuquerque and receiving the medical attention he needs but his condition is not known to the public as yet.
"Please take a moment in your day today to think about him and send positive thoughts and prayers his way, thank you."