The 23-year-old was signed by Sundowns at the start of the season but remained on loan at TS Galaxy for the first half of the campaign.
Reports suggest his move gained momentum after he was left out of Galaxy's 1-0 Betway Premiership defeat to Sundowns, fuelling speculation that he was already en route to Chloorkop.
With Sundowns trailing Orlando Pirates by two points after 13 league matches, the reigning champions have acted quickly to bring the Bafana Bafana defender into their squad as the second half of the season kicks off later this month.
Ndamane was part of South Africa's squad at the 2025 Africa Cup of Nations (AFCON), which ended in disappointment following a round-of-16 exit to Cameroon. Although he did not feature in any matches, he remains firmly in head coach Hugo Broos' plans.
The KwaZulu-Natal-born defender, a former Kaizer Chiefs academy product, impressed in Bafana Bafana's 3-0 FIFA World Cup qualifying win over Rwanda in October, deputising for the suspended Mbekezeli Mbokazi.
Since joining TS Galaxy last season after leaving Chiefs, Ndamane has made 42 appearances in all competitions, registering two assists.
Ndamane is expected to make his Sundowns debut when the club hosts Orbit College at Loftus Versfeld Stadium on 19 January, a day after the AFCON concludes on 18 January.
Mamelodi Sundowns have sent shockwaves through South African football by pulling off one of the most unexpected moves of the transfer window, snapping up Monnapule Saleng from fierce rivals Orlando Pirates.
Mamelodi Sundowns goalkeeper coach Kennedy Mweene insists they remain firmly on course to compete for honours both domestically and on the continent.
Siwelele FC are reportedly assessing clubless former Premier Soccer League winger Kgaogelo Sekgota ahead of the resumption of the second half of the season.
Mamelodi Sundowns attacker Miguel Reisinho is determined to help his new team win silverware this season.
