At least six teams are involved in negotiations to acquire Pence, according to a person close to the situation. No deal is imminent, and Astros general manager Ed Wade declined to comment when reached at the team's offices in Houston.
Pence admitted following Thursday night's win over the Cardinals that he couldn't help but think he might have played his last game in an Astros uniform.
"What can I say? I'm not in control," he said. "I love these guys, I love Houston. That's all I know."
KRIV-TV in Houston reported on its website Thursday the Reds, Phillies and Braves, along with three teams in the American League, are in the negotiations. The Phillies have made Pence their top priority and they have the depth in the Minor Leagues to pull off a deal.
Interest in Pence has picked up since Carlos Beltran was acquired by the Giants in a deal that was finalized early Thursday.
ESPN.com reported Wednesday the Astros had turned down a proposal from the Phillies earlier this week that would have sent pitching prospect Jarred Cosart and hitting prospect Jonathan Singleton, among others, to the Astros.
Astros manager Brad Mills said he spoke to Pence a few days ago to try to ease his mind amid the flurry of trade rumors in advance of Sunday's 3 p.m. CT non-waiver Trade Deadline. Mills admitted it's hard to ignore trade rumors, but he wanted Pence to get away from it as much as he could.
"When you come to the ballpark, prepare and do what you can for that game, that night and go from there," Mills said he told Pence.
Pence, 28, is hitting .309 with 11 homers and 62 RBIs and made the National League All-Star team for the second time. He's making $6.9 million this season and still has two years of arbitration remaining, so any team acquiring him would have him under control for at least two more seasons.
Pence is the Astros' best and most popular player, but the club is in a major rebuilding phase and is trying to land some premium prospects in exchange for Pence. The club has also fielded offers for pitchers Wandy Rodriguez, Brett Myers and outfielder Michael Bourn.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.