Middlesbrough boss Gareth Southgate says he'll look to introduce his summer signings to the first team in the coming weeks.
"Didier was desperately disappointed not to start because he's done well in pre-season, but we had lots of attacking players in the team and Shawky is more defensively minded," Southgate said after victory over Tottenham.
"Marvin is a player we've bought for the future but in pre-season he made a big impact.
"Justin has got great pace and terrific pedigree and we're delighted to get his signature."