The first baseman, who has been sidelined since June 4 with a left index finger fracture, is hoping to return for Friday night's series opener in Pittsburgh.
On Tuesday, Pena took batting practice with the team and did his most extensive workout since the injury. He said head athletic trainer Ron Porterfield wanted him to replicate the same workout on Wednesday and make sure there wasn't any excruciating pain.
Although Maddon was not definite on Pena's activation coming on Friday, the 29-year-old was still excited at the prospect of finally being out on the playing field.
"I can't wait," Pena said. "I was like that a week and a half ago ... but I understand that I have to be smart, especially when the doctors tell you, you can't play with that [injury]."
The return of Pena would allow a lot more flexibility for the Rays infield, which is expected to be without Jason Bartlett until Friday, as the shortstop's wife delivered the couple's first child late Wednesday afternoon.
Second baseman Akinori Iwamura will also miss several games, although his timetable is a bit fuzzier.
Iwamura appealed his three-game suspension on Wednesday afternoon -- for involvement in the fracas with the Red Sox on June 5 -- and the team is unsure when the infielder's exact punishment will be doled out.
Pena's activation would allow Willy Aybar to shift over from first base to fill in for Iwamura at second.
In the event that Pena is not deemed ready on Friday and Iwamura is suspended, Maddon said the club will opt to put Eric Hinske at first and have Aybar assume Iwamura's role.
Aybar was not in Wednesday night's starting lineup and was seen speaking with Maddon prior to the game, but the skipper said there are no pressing issues.
"All positive things," Maddon said of his talk with Aybar. Although the infielder's playing time will substantially decrease with the scheduled return of Pena, Bartlett and Iwamura, Maddon said Aybar's performance has "made a good mark" on him, and was a point he wanted to reemphasize.
Brittany Ghiroli is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.