Newcastle United assistant manager Ian Cathro has insisted that the players have a lot of work to do in pre-season in order to get themselves ready for the new Premier League campaign.
"We're in pre-season and there's a lot of work that needs to be done," Cathro told the club's official website. "There are not many parts of this industry that are Monday to Friday, nine-to-five.
"This is all the time or none of the time. You're either in or you're out, and in order for us to achieve the things that we need to achieve, everyone needs to be in."
McClaren's first league game in charge of the Magpies will be against Southampton at St James' Park on August 9.