The 48-year-old joined Boro in May 2018, while many supporters have criticised the club’s recruitment policy in recent years. We take a closer look at the 14 players who have signed for the Teessiders over the last 18 months – loans and permanent deals. Scroll down and flick through our picture gallery to see the full list:
9. Rajiv Van La Parra - January 2019
Signed to provide some much-needed pace out wide, the Dutch winger played just 68 minutes of Championship football for Boro. His loan spell from Huddersfield was cut short due to a back injury. Photo: Stu Forster
10. John Obi Mikel - January 2019
Tony Pulis revealed he visited Mikel's house to seal a move to the Riverside. After a decent start, the midfielder's performances tailed off towards the end of his short-term contract. Photo: George Wood
11. Tomas Mejias - July 2019
Boro re-signed Mejias as back-up for Darren Randolph, yet the Spanish goalkeeper is yet to make a senior appearance this season. Photo: Shaun Botterill
12. Marcus Browne - July 2019
It's been a difficult start to the attacker's Boro career. Most of Browne's appearances this season have come off the bench while a hamstring injury and reckless red card haven't helped his cause. Photo: Getty Images