Marcus Rashford was left out of the provisional 33-man squad for Germany and there has been talk that Grealish could be the next big name axed with Southgate set to cut the squad to 26 players by June 7th.
Grealish made just 20 Premier League appearances for Manchester City this season, scoring three goals, and was an unused substitute in their FA Cup final defeat by Manchester United last month.
Asked if Grealish was in danger of missing out, Southgate said: "I don't think we’re defining that just yet. I think we know where we're likely to be.
"I haven't talked to him specifically about the Cup final. But he has been really bright and he loves being here.
"This season he has not played as much. I'm sure he would have liked that to be different but we know the qualities he can bring. He is a player we enjoy working with."
Southgate added there was time for people to impress in friendlies against Bosnia and Herzegovina and Iceland this week.
The likes of James Maddison, Eberechi Eze, Cole Palmer and Jarrod Bowen are all pushing for berths in the squad and Southgate said he had not settled on how many attacking players he would need.
"What we don't totally know is how many we need to take or how many we can allow ourselves to take because of the cover we might need in other positions as well," he added.
England host Bosnia at St. James' Park later on Monday and Iceland at Wembley on Friday before opening their Euro 2024 campaign on June 16th against Serbia in Group C.