#1 Time for Joe Gomez to play as a regular centre-back?

No, not because Klavan and Matip have been all that bad. Considering how good Trent Alexander-Arnold has been, it's about time he gets regular games. Gomez is more of a natural centre-back, versatile enough to play as a full-back. But considering Liverpool's style of play, Alexander-Arnold offers more going forward than Gomez.
Gomez's strength is while defending, so why not give him a run out at the heart of the defence? Liverpool have lacked options there and keeping in mind what Klopp said regarding winter signings (scepticism), Gomez is a pretty good option at centre-back.
With an FA Cup tie coming up, it's perhaps the best time to experiment with Gomez. Mind you, Nathaniel Clyne's return is due come early February, so Klopp could have a few options up his sleeve.