That’s according to former Premier League star Joleon Lescott who reckons the stars will have been unsettled by their respective transfer sagas.
Van Dijk was heavily linked with a move to Anfield throughout the summer.
However, Southampton dug their heels in and refused to let their prized asset leave.
The former Celtic star handed in a transfer request - but a deal failed to materialise despite weeks of speculation.
Meanwhile Costa has been in Brazil after he was deemed surplus to requirements at Chelsea.
The maverick forward wanted a move to Atletico Madrid, but that’s not been possible with the La Liga side under a transfer embargo.
He’s not expected to feature for Chelsea this season having missed all of pre-season during his self-imposed exile.
“I’d say probably Diego and Virgil van Dijk (will struggle the most out of players who wanted to leave),” Lescott said on Sky Sports.
“Due to the fact them not being able to train with the first-team and play any games.
“The rest of them have obviously made it clear they do want to move but they’ve been able to train and still perform at a level that is not that far away.
“A lot of them have played international games so they’ve still got some level of fitness.
“So I think for them two it will be hard.”
