Aitor Karanka
Aitor Karanka is frustated with the number of injuries in his squadGetty

Middlesbrough manager Aitor Karanka has admitted concerns over the number of injuries in his squad ahead of the Capital One Cup trip to Manchester United on 28 October, with fitness doubts hovering over Stewart Downing, Albert Adomah, Adam Forshaw and Cristhian Stuani. In more positive news, the club has confirmed the signing of Bruno Zuculini on a month-long loan deal from Manchester City to bolster its midfield.

Boro visit Old Trafford looking to book their place in the quarter-finals of the League Cup having previously knocked out Oldham Athletic, Burton Albion and Wolverhampton Wanderers. The Championship side arrive to the game in a good mood following their league 3-1 win over Wolves at the weekend thanks to goals from Diego Fabbrini, Grant Leadbitter and Downing, but may face Manchester United without a number of key players.

Downing himself started Saturday's game on the bench as he was carrying a knock, while Adomah suffered a twisted ankle during the match, which may him leave on the sidelines for the trip to Old Trafford. Meanwhile, Forshaw and Uruguay international Stuani missed the game and it is unknown if they will be fit for the match with Louis van Gaal's boys.

"In all my time here we haven't had a lot of injuries, but we have been missing Stuani and we now have Albert as well with his ankle," Karanka said, as quoted by the club's website. "I don't know how he will be for Wednesday. Adam Forshaw has also picked up an injury as well. We will have to wait and see over the next few days."

Karanka, who was Jose Mourinho's assistant during the Chelsea manager's time at Real Madrid, has also the long-term injuries of Alex Baptiste, Rhys Williams, and Damia Abella to contend with.

The club, meanwhile, has confirmed the arrival of 22-year-old Zuculini on a month-long loan from Manchester City to bolster Karanka's midfield ranks. While Forshaw is doubt for the trip to Old Trafford, Leadbitter and Adam Clayton are just one more booking away from suspension.