Baltimore Orioles second baseman Brian Roberts showed improvement in his strained right rotator cuff, though not enough for Manager Lee Mazzilli to put him back into the lineup.

Mazzilli said Monday that Roberts, who has been out of the lineup since June 1, likely will return Tuesday or Wednesday.

"He convinced me that he's healthy and getting better," Mazzilli said. "I think right now he's going to have to be the judge whether it's Tuesday or Wednesday."

Prior to Monday's game, Roberts ran and threw on the field and reported no pain.

Bigbie, Matos Improving

Left fielder Larry Bigbie also is showing improvement in the strained left hamstring that put him on the disabled list.

Mazzilli said Bigbie likely will go on a rehabilitation assignment this weekend. . . .

Luis Matos, out since May 10 with a fractured right ring finger, hit with both hands for the first time Monday and may be a week from a rehabilitation assignment.

"It's just a matter of getting his arm ready so he can throw from the outfield," Orioles trainer Richie Bancells said. . . .

Monday was the first time the Orioles had played in Pittsburgh since the 1979 World Series. The Orioles led three games to one in the series before losing the final three games, including Games 6 and 7 in Baltimore.

"The '79 series wasn't bad except for the outcome," former Orioles catcher and current first base coach Rick Dempsey said. "That was our first World Series for a lot of us. We weren't supposed to be as good as the Pirates. Once they got the momentum after Game 4, they were hard to beat."