Swansea City manager Brendan Rodgers is hoping to sign up to four new players on transfer deadline day.
The Premier League newcomers are in talks with Fulham about a possible move for Algerian defender Rafik Halliche.
Watford defender Adrian Mariappa and Middlesbrough defender Matthew Bates have also been the subject of enquiries by Swansea.
"I hope to bring in up to three, maybe a maximum of four, and I will be relatively happy," said Rodgers.
"It is our first year so we are not going to go stupid, we don't want to spend fortunes."
Swans coach Alan Curtis had already said their "urgency" to bolster their defence has become greater because Alan Tate is to miss most of the season following a freak golfing accident.
The versatile defender is set to be out for six months after breaking his left leg when he was a passenger in a golf buggy that lost control on Sunday.
Rodgers must complete any deals before the transfer window closes at 2300 BST on Wednesday.
"Defence is an area I have felt we needed to strengthen," said Rodgers.
"I wanted to bring in two players in that area anyway for that supporting cover but Alan's injury has made it a priority.
"We just want to bring in the best players and not so much numbers, but ensure we have quality in the squad.
"I don't like to stockpile players. We want to ensure the players contribute.
"We will try and do our business behind the scenes and once we confirm any deals we will make that news."
Rodgers has no experienced cover for his full-back positions and the Welsh club have only three experienced centre-backs, so Rodgers wants depth to cope when Ashley Williams, Steven Caulker and captain Garry Monk are out with injuries.
Bates is a 24-year-old former England youth international and can play anywhere across the back.
Both Mariappa and Algerian international Halliche, who played just twice for Fulham since joining the Craven Cottage club in August 2010, are central defenders.
Wales international Williams hopes Rodgers can sign new players before the transfer deadline.
"The manager was probably looking for a bit of cover before," he said.
"And now with Tate being out and him being so versatile, we definitely need a few players now.
"The gaffer will probably be in control of that situation."