The 37-year-old has been a remarkable success since joining Barcelona from Bayern Munich in 2022, scoring 113 goals in 174 games.
Despite his impressive form, Lewandowski’s hefty wages mean Barcelona are yet to offer him a new deal, with his current one set to expire at the end of the season.
Speaking ahead of Barca’s La Liga clash with Mallorca on Saturday (February 7), Flick insists a decision is yet to be made.
"What I feel now is that we've spoken several times. He shouldn't be thinking about next season; he needs to focus on this one," he said.
"He's doing a good job; sometimes he wants to play more, in important matches, 90 minutes, but it can't always be like that.
"He loves playing for Barca, we'll see what happens at the end of the season. We don't know what might happen, it's not the time to talk about this. We have stability and we want to maintain it in the future. There will be time."