Brendan Rodgers has confirmed Swansea City have enquired about signing Middlesbrough captain Matthew Bates.
The Premier League newcomers want to strengthen their defensive options and have been in talks to sign 20-year-old Liverpool centre-back Daniel Ayala.
England youth defender Bates has also caugth Rodgers' eye but Boro insist no offer has been made.
"They are players who we are interested in," said Rodgers. "But they are at other clubs."
Young Tottenham Hotspur defender Steven Caulker is one of Rodgers' six summer signings as the Swans boss prepares his Welsh side for their first Premier League campaign.
Wales international Ashley Williams will be Swansea's defensive lynchpin in their Premier League opener at Manchester City on Monday.
Captain Garry Monk could miss the trip to the Etihad Stadium with a foot injury so loan signing Caulker could make his debut alongside Williams.
But Rodgers wants to bolster Swansea's backline before the transfer window closes and he has to name his 25-man Premier League squad by 2 September.
"It is certainly an area we want to strengthen," Rodgers said.
"It is different in the Premier League as once you name your squad, that's you through to January - so we must make sure we have enough quality and reinforcements."
Bates, an FA Youth Cup winner in 2004, has endured a difficult time with injury and suffered a series of serious knee injuries.
The Middlesbrough academy graduate was limited to less than 80 appearances in his first seven seasons - but Bates, who has a year remaining on his Riverside deal, made 32 appearances last season.
"I spoke to [Boro manager] Tony Mowbray on Matthew and on his availability to see where he was at," said Rodgers.
"There is a number of players that we are looking at but I am not in a rush."
Bates featured in Boro's 2-2 opening day draw with Portsmouth and manager Mowbray hopes to keep his skipper.
"I have had one conversation with Brendan and then nothing," he said.
"I said to Matthew [Thursday] morning that nothing has happened, there has been no further conversations, there has been no offers, it is just speculation.
"He needs to get his head around the fact he is captain of Middlesbrough Football Club, he's got a big game at the weekend and he has to get himself ready."