Sunderland failed in an attempt to sign Dnipro Dnipropetrovsk defender Ivan Strinic last summer, according to the player's agent.
The Black Cats, along with Russian outfit Dynamo Moscow, were strongly linked with Strinic, 25, during pre-season, but the Croatia international has remained in Ukraine.
"We received a concrete proposal from Sunderland, but Dnipro rejected the deal," Tonci Martic told Tuttomercatoweb.
"With regards to Dynamo Moscow, there have been no formal negotiations, but maybe something will change in the summer."
Strinic has been capped 26 times at senior international level.