Watford head coach Oscar Garcia will undergo further tests in hospital, following a health scare over the weekend, according to Sky Sports.
The 41-year old was admitted to hospital on Sunday with minor chest pains, less than a day after his first game in charge.
Having spent the night under observation, the Spaniard missed his side's 1-0 win over Blackpool last night and is looking unlikely to oversee his side's game against Bournemouth on Saturday.
Hornets won't rush the Spaniard as health concerns remain
The club have said they won't rush their new head coach back and are prepared to wait until the former Brighton boss feels he his totally ready to return to his managerial duties.
This comes as a blow for Watford fans, who were stunned when former manager Giuseppe Sannino resigned with the side just one point off the top of the Championship.
Currently in second place behind Norwich, Watford have started well and find themselves in the mix at the right end of the table, with a concerted promotion charge very much the aim.
Promotion challenge very much the aim
Fans would have high hopes of a successful season, after seeing Garcia lead Brighton into the playoffs last season, only to be defeated by a resurgent Derby County side.
After being relegated in 2007, it has been a long wait for Watford fans to see their side return and expectations will be higher than ever that this season can see them achieve their top flight ambitions.
In Garcia's absence assistant coaches Ruben Martinez and Javier Pereira have been in charge and will continue in that role until he is given a clean bill of health.