Middlesbrough FC transfer latest: Zack Steffen signing is a 'big coup' insists Chris Wilder

The 27-year-old has completed his move to Teesside on a season-long loan and is expected to be the club's new number one for the forthcoming season.

The USA international, who signed a new four-year contract with City last November, is set to make his debut in Boro's friendly at Morecambe on Tuesday night.

Steffen, who has Premier League and Champions League experience and also played a season on loan in the Bundesliga with Fortuna Dusseldorf, has been capped 29 times by the US.

Wilder said: "I think it’s a big coup for us and so I’m delighted we’ve brought Zack in.

"We knew we had to improve the goalkeeping department. We brought in Liam Roberts and now we’re adding Zack who has just signed a four-and-a-half-year deal with Man City.

"Man City don’t hand out four-and-a-half-year contracts if they don’t think anything of them.

"Everyone knows his situation, he needed to play because of the World Cup. He had an agreement with Man City, but he could have easily stayed there and sat comfortably as their number two. He wanted to go out and he’s agreed to come here.”

The move brings an end to Boro's search for an established senior keeper, with the club having been linked with a number of names including Karl Darlow and Tom Heaton.

Earlier on Tuesday, Boro completed the sale of Djed Spence to Spurs for an initial £12.5m, with the fee to rise to almost £20m with add-ons.