The former Tottenham center-half has been impressive for the Lions in the Championship.
Now he may have earned a move back to the top flight, with Wolves said to be showing interest in his services.
Per The Express, many at The Den feel that Tanganga will move away sooner than later.
Millwall hope to retain the defender for the rest of the season, but cannot resist big money offers.
Former Millwall boss Neil Harris praised Tanganga in November, saying: "I get on brilliantly with Japh.
"I just promised him rhythm, games, doing the best we can to keep him fit and giving him a platform to enjoy his football, and to restart and kickstart his career again, because he’s a Premier League player all day long, we all know that.
"We want him on the pitch every week and he knows his place in the team. I know what he’s excellent at, which is pretty much everything."