The 22-year-old is yet to feature this season and will miss Saturday's Premier League trip to West Brom as he continues his rehabilitation from a hamstring injury sustained in Chelsea's FA Cup Final defeat to Arsenal on Aug. 1.
Pulisic's debut campaign in England following a £58 million move from Borussia Dortmund was a mixture of fine form and persistent problems, becoming the youngest Chelsea player to score a hat trick in the Premier League but also making just 27 starts in all competitions.
The USMNT international suffered multiple injury setbacks including a abductor tear in early January which restricted him to a total of 1,727 minutes out of Chelsea's 4,950 total.
And Lampard said: "There is always a concern about players' fitness when the history says there has been some injuries and last season we did have it with Christian. I was questioned many times on my position on Christian when he did play and didn't play.
"Of course, when you look at a player with his recent record, you are trying to find the right way, the right balance of getting the best out of him which we saw in big periods last year and making sure you don't overcook him and leave him susceptible to injury, particularly a player of his explosive pace and balance. That's a fine line.
"We are working on that and Christian is also very open to that. He wants to play, he is so hungry to play and he is very nearly fit now but it is certainly something we will have to manage with him this season because we have all seen the talent and it is something we want to get right. I am not saying it is a fundamental chronic issue, it's not. But we want to get as many minutes of the really great Christian we saw lots of last season on the pitch."
Although Pulisic will miss Saturday's game, Lampard was upbeat about the prospect of a quick return to action.
"Christian isn't ready for the squad tomorrow -- nor is Hakim Ziyech -- but they are both training with us now which is good news and we hope to have them with us in proper match contention over the next week or two," he added.