Johnson, 32, will undergo surgery in the new year after sustaining a season-ending cruciate knee ligament injury in last weekend's home win over Brighton. He is expected to be sidelined for up to nine months.
Clark told the Huddersfield Examiner: "As for his long-term future, we will look at the situation at the end of the season.
"No decision has been made yet, but he has impressed so many people here and we will monitor how things progress."
Source: PA
Source: PA