Chris Chester, Scott Murrell and Rob Nickolay will lead the team in his absence and they will be supported by club legend and Man of Steel Adrian Vowles.
Australian Carr took charge in pre-season on a three-year deal having previously been coach of Featherstone Rovers and assistant manager at Leeds Rhinos in 2019.
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A statement released by the club read: "Castleford Tigers RLFC can confirm that head coach Ryan Carr will not be in attendance at the Hull KR game this coming Friday. We can confirm that this is due to personal reasons, contrary to the reports on social media.
"In the interim, Chris Chester, Rob Nickolay and Scott Murrell will lead our on and off field operations. This leadership group will be heavily supported by Adrian Vowles and we thank Adrian for offering his support at short notice.
"We will not be making any other further comment at this stage, and we urge our fans to once again get behind our team this coming Friday."
Castleford currently sit ninth in the Super League table with seven wins from 21 games.
With six games remaining in the season, they face the Robins followed by Hull FC, St Helens, Catalans Dragons, Bradford Bulls, and Huddersfield Giants.
Sky Sports will show every game of the Super League live this season, including two matches each round exclusively live. The remaining five matches will be broadcast on Sky Sports+.
