The 29-year-old centre-back is a free agent having been released by League One club Wanderers at the end of last season.
Portugal-born Santos was at Dagenham and Redbridge as a youngster and played non-league football before being handed his EFL chance by Peterborough United in 2014.
He played 75 games for Posh before spending three and a half years at Barnet.
After joining Bolton in 2020, Santos made 207 appearances for the club – including 32 last season – and was skipper between October 2021 and September 2024.
Should a deal be completed, Santos would follow on from the captures of Bobby Wales and Zeidane Inoussa, while Melker Widell is also set to finally link up with the squad this summer following his move from AaB in January.
Santos will add to Alan Sheehan’s depleted defensive options following the departures of Kyle Naughton, Cyrus Christie and Kristian Pedersen – as well as loan signing Hannes Delcroix – this summer.
Swansea Bay News understands that Santos is likely not to arrive as a potential replacement for Darling, and is arriving to add extra cover, with Ben Cabango currently the only recognised senior centre-back on the books for next season.
Uncertainty continues about the future of first-choice central defender Harry Darling, who is out of contract this month, with the 25-year-old believed to have attracted interest from the likes of Birmingham City and Wrexham.
However, Swansea have indicated that the signing of Santos is unrelated to Darling’s situation, with the club still hopeful a new deal can be agreed.
[Lead image: Bolton Wanderers FC]
