Jackson is back after suspension following his red card in the defeat to Flamengo.
With fellow strikers Joao Pedro and Liam Delap signing since the end of last season, talk has emerged of Jackson being on his way after the US tournament.
Maresca said on Monday: "Nico is ok, and then in terms of game plan for tomorrow, I think every game, we try to adapt a little bit, ourselves, in terms of finding solutions. Tomorrow we are going to move on, we are not going to settle the same.
"Nicolas is training well, unfortunately, almost the last two games he played he was sent off, he was red card, unfortunately for him, unfortunately for us, but he's working well, he played after the Newcastle red card, he played the Conference League final, he scored, we won, and then for the new season, also for the future, we decide to bring another No.9, and at this moment, it's okay."
On fresh striker competition, the Italian added: "For sure, I think Joao, Liam, Nico, the ones that we have at the moment, they know exactly about No.9 at Chelsea. But I said already many times, in my mind, or in my idea, I prefer to have four or five players scoring 10-12 goals each, than just one striker scoring 40 goals.
"So, you can see last year, what we have done with Noni (Madueke), what we have done with Enzo Fernandez. And we expect next season, more goals from all our attacking players. But for sure, as I said, the ones that they are playing as a No.9 with us, they know exactly Chelsea's style."