European's elite competition could be a vital factor in any possible deal though as RB Leipzig are fighting for qualification into the Champions League and may want to hold on to such a player.
Rumours in Germany have insinuated that Keita's last game for Leipzig will be played this weekend against Schalke before he finally moves to Merseyside to join the Reds.
Jurgen Klopp was coy when quizzed over a potential early Liverpool arrival for Naby Keita.
"There are no inquiries or offers for any player who is on the pitch on or the bench for us today from any club", said Rangnick, who added that an increased offer would make no difference. He might have got another for a foul on Max Meyer before Leipzig coach Ralph Hasenhuettl chose to take him off with just over 20 minutes remaining.
RB Leipzig confirm Naby Keita will not join Liverpool in January
However, after Hanover striker Niclas Fuellkrug made it 2-1 with a header towards the end of the first half, De Jong brought down midfielder Felix Klaus in the area and the referee pointed to the spot.
The defeat leaves Mainz 15th in the table, just a point above the bottom three, while Hanover climb to 10th.
Will we see the Guinean touch down in the Premier League before the end of the month, though? The 32-year-old Gomez's career began with Stuttgart youth sides before he helped the senior side win the Bundesliga in 2007.
Augsburg defeated Hamburger SV 1-0 to leave the visitor stuck in the relegation zone.
Werder Bremen and Hoffenheim played out a 1-1 draw as Czech worldwide Theodor Gebre Selassie's second-half goal for hosts Bremen cancelled out Benjamin Huebner's first-half header.More news: What Nancy Kerrigan thinks of 'I, Tonya'
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