Berkman, who went 3-for-4 with a homer and a double in his second of two rehab games on Sunday at Triple-A Round Rock, said he spoke with Mills from Chicago following the Astros' 3-2 win over the Cubs and told the manager he's ready to play.
Berkman underwent arthroscopic surgery on his left knee on March 13 and hasn't appeared in any games for the Astros this year.
"I've already talked to Brad Mills and tried to call [general manager] Ed Wade," Berkman said via phone. "[Mills] asked me if I could go Tuesday, and I said, 'Absolutely.' He said is this the type of thing where we're going to have to nurse you along, and I said, 'No, you can run me out there for about 10 or 15 games and see what happens.' I anticipate being in the lineup on Tuesday and not coming out of it until the end of the year."
Berkman's return will come at a good time for an Astros team that is hitting .215 with three homers through the first 12 games of the season. The Astros rallied to win in 10 innings on Sunday and head to Houston having won back-to-back games and three out of four.
He said the knee isn't completely healed, but it's well enough for him to play.
"I wouldn't say it's completely behind me, but I would say it's good enough to get out there and play," he said. "I hadn't played a game in five weeks, so obviously not just my knee, but every part of me is kind of sore, just because I hadn't been in game action.
"But this is definitely to the point now it's manageable. Before, when I tried to push it that one day [late in Spring Training], I just could not do it. But this is different. It's still a little bit swollen, but it's manageable."
Berkman hit .274 with 25 homers and 80 RBIs in 136 games last year with the Astros and missed 18 games with a strained calf. He ranks in the top 10 in every major offensive statistical category in Astros history, ranking second in home runs and third in RBIs, walks, doubles, runs and total bases.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.