"Glee" season 6 will be the final season of the hit musical drama series, which means that it is time for all the show's characters to say goodbye to their fans. But the series finale will also be the perfect time for past guest characters to reappear in the show. 

One of the returning guest characters this season is Santana's (Naya Rivera) mother Maribel, played by internationally-acclaimed singer Gloria Estefan. The singer-actress confirmed her return to McKinley High through a series of Instagram posts, showing herself with her on-screen daughter and Santana's partner Brittany (Heather Morris). 

Estafan was first seen in the series during season 3 episode 22 titled "Goodbye," wherein she portrayed a very supportive mother when her daughter came out as a lesbian, but was sad when she found out that Santana was planning to move away to New York. 

Maribel's appearance this season fuels speculations that she will lend a hand in her daughter's alleged wedding to Brittany, although this is not yet confirmed. 

Meanwhile, another promo teaser was released. This time, it features a duet between Blaine (Darren Criss) and Rachel (Lea Michele), singing Little Shop of Horrors' "Suddenly Seymour." The trailer starts with Will Schuester (Matthew Morrison) rehearsing his new glee club, the Vocal Adrenaline. 

There are also brief footages showing a disappointed Rachel leaving a studio where she failed in her TV acting career. She then leaves the studio to return home to Lima, Ohio. Then she sees Blaine who tells her that he is now the new coach of the Warblers. This means that Blaine, Mr. Shue, and Rachel will be pitting against each other, since Rachel will also spearhead their old glee club, the New Directions. 

The video trailer also shows Professor Figgins, the former McKinley High principal who was demoted by new principal Sue Sylvester (Jane Lynch), working at the Lima Bean coffee show. 

The "Glee" season 6 premiere episode airs Jan. 9 on FOX.