Kerr was sidelined after she suffered the ACL injury at a warm weather training camp in Morocco last year.
The 31-year-old, who joined Chelsea in 2019, has scored 99 goals in 128 matches for the London side, winning the league five times, the FA Cup three times and the League Cup twice.
"Sam is in a good place. She's been training well, she's physically in a good position and she's also mentally in a good place," Bompastor said ahead of Friday's Women's Super League opener against Manchester City.
"I think she's one of the players everyone wants to see on the pitch. It's nice for me to have her in the squad with her leadership experience.
"But at the same time, we have to be patient with her because she's been away from the pitch for a long time. She's not at her best level yet, but hopefully that will come soon. It's already a good step for her to be in the squad."
Kerr had averaged nearly 30 goals in the previous three seasons for Chelsea before she was injured in the 2023-24 campaign.
A two-time winner of the Golden Boot, Kerr also finished runner-up to Spain's Aitana Bonmati at the Ballon d'Or awards in 2023.
But more than her goals, Bompastor said Kerr's presence alone was a boost as she saw the forward as one of the leaders of the team that have now won six successive WSL titles.
"She's a really smart footballer. I really enjoy watching her, making those good runs with the right timing. With these kinds of players, you don't really teach them how to play football - they already know how to do that," she added.
"For me, it's more about giving them all the confidence to be the best version of themselves on the pitch, but also sometimes I can give some more details about when to make the run, how to do something even better.
"I've tried to help in that sense, but Sam is a great player and she doesn't need much. Sam is in the squad, so she will be involved in the game, but we don't know yet if she will start or if she will be on the bench."