The 28-year old Scotsman arrived at St James' Park recently following spells with Dundee United as youth coach, as Nuno Espirito Santo's assistant with Portuguese club Rio Ave and again as Nuno's right-hand man at Valencia last season.
McClaren says the acquisition of Cathro, as well as his other backroom staff, certainly has things in good shape as the Magpies look to turn things around following a disastrous 2014/15 campaign.
"He (Cathro) worked in Portugal for two years and at Valencia, in the Champions League and La Liga," McClaren told Sky Sports News HQ.
"For one so young, he has a lot of experience and he is using that out there to control the players and coach them and he is doing very well.
"It's not just about myself coming in, it's about the staff that we've brought in, and we've got great staff."