Kaiserslautern have confirmed that head coach Jeff Strasser did not suffer a heart attack during Wednesday night's abandoned 2.Bundesliga match against SV Darmstadt 98.
The 43-year-old was taken ill midway through the game, which was subsequently called off with the scoreline goalless.
German media reported that Strasser had suffered a heart attack, but a statement by Kaiserslautern ruled this out, confirming that the former Luxembourg defender went to hospital and is awaiting the results of further tests.
"After examinations in hospital in Darmstadt, a heart attack to Jeff Strasser has been ruled out," said the statement.
"Over the course of the coming days, further cardiological tests will be carried out in order to make a definite diagnosis."
Red Devils assistant manager Alexander Bugera has taken over preparations for Saturday's meeting with Fortuna Dusseldorf.
Officials have decided that the original tie with Darmstadt will be replayed in accordance with league rules.