Reds manager Brendan Rodgers told the Liverpool Echo via ESPN:
We want to keep Glen here. There is no question about that, especially now he's in this form. He's 29 and we feel that he has still got good years ahead of him.
No contracts will be looked at until the summer but his will be a priority for us, especially if he continues in the form that he's in.
Rodgers may have felt it necessary to underline the situation with Johnson, whose contract runs out in 2015, because of the attentions of the La Liga giants.
John Percy of the Daily Telegraph notes that the player has emerged as a "realistic target" to join Carlo Ancelotti's side in the summer.
Johnson himself is keen to stay on Merseyside, but he told the Daily Mail via ESPN:
I've loved every minute of the five years I've been here and I'd love to stay but really the only truth in it is that I've not been offered a new contract on any level. [...]
It is an unnecessary distraction.
Whether the Reds would be willing to match any larger salary offers from elsewhere is debatable.
ESPN notes that Fenway Sports Group have been reluctant to increase the salaries of players who are 30 plus, with Johnson reaching his 30s this August.
Indeed, there is a suggestion that Johnson may have to take a pay cut on his £110,000-per-week wages.
Clearly Liverpool fans think Johnson would be worth every penny of a new deal:
Despite a mid-season injury, which kept him out for seven weeks, Johnson has begun to find his best form again and his importance to Rodgers' red revolution is obvious.
During the most recent matches, he has often had to fill in at left-back, alternating with another natural right-sided player in Jon Flanagan. Both have been utilised by Rodgers there because of the long-term injury to Jose Enrique and the poor form of on-loan Valencia man Aly Cissokho.
It's a role that Johnson has played with equal aplomb as his stats from the recent match against Southampton show, per WhoScored.com.
With eight Premier League matches left until the end of the season, Johnson has ample opportunity to make any Liverpool contract talks a formality.