Everton and Newcastle are reportedly interested in Villarreal forward Ivan Alejo.
The 19-year-old defender made his second straight Premier League start on Saturday as Black's side drew 0-0 with the Magpies at Villa Park.
The midfielder has been on loan at the Yorkshire club this season.
The duo have not impressed for Celtic this season.
The Italian was keen to focus on celebrating Swansea's fine win over West Ham on Saturday, adding that he is tired of speculation surrounding his future.
Queens Park Rangers won 1-0 against Bristol City at Loftus Road yesterday.
The West Ham United captain has been in fine form for his side this season.
Arsenal are expected to be busy in the summer transfer window, and perhaps defence will be their focus.
The current manager is set to leave Celtic in the summer.
The Sunderland midfielder was highly impressive in the win over Chelsea.