Just over a week ago, the Orioles were a division foe to John Lackey.
So he'll be plenty familiar with them, and vice versa, as St. Louis and Baltimore continue their weekend series at Oriole Park at Camden Yards on Saturday.
The Orioles took the series opener, 12-2, Friday night.
Saturday will also mark Ubaldo Jimenez's return to the Orioles' rotation. The right-hander will be making his first start since July 5 after a stint on the DL for a right ankle sprain.
"I'm very happy about it," Jimenez said of his impending return. "Definitely I'll be happy to get out on the mound and to be there for the team and help them out. And what is our goal and that it is win the division."
Jimenez, who has struggled this season with a 3-8 record and a 4.52 ERA, said the ankle is no longer bothering him. He admitted, though, that he'll be a little anxious to return to the mound with his team atop the AL East.
"But I'll be able to calm down," he said. "I know I'm going to be thinking about it as just another game, but definitely it's not because it has been a while since I've pitched over here and I'm very excited about it."
Lackey, meanwhile, who went from the Red Sox to the Cardinals at last week's non-waiver Trade Deadline, should feel right quite comfortable in Baltimore's visiting clubhouse.
The big right-hander has made 26 career starts against the Orioles, notching a 14-7 record to go along with a 3.70 ERA.
In his first start with St. Louis, against the division-leading Brewers, Lackey threw seven innings of two-run ball.
"From the start, my arm felt good," Lackey said after earning his 150th career win. "I started locating some balls better as the game went on."
Cardinals: Club relying on Lackey and Pierzynski for scouting
St. Louis picked the right season to acquire a pair of former Red Sox.
The Cardinals will rely heavily on the knowledge of Saturday starter John Lackey and catcher A.J. Pierzynski in compiling their scouting reports for the Orioles.
Pierzynski started the season with Boston, while Lackey came over last week at the Trade Deadline.
"I think it's going to be an advantage to us compared to most Interleague games where we're going in blind," St. Louis manager Mike Matheny said.
Pierzynski is expected to start behind the plate Saturday because of his familiarity with Lackey. He caught 18 of Lackey's starts with Boston this season and also caught the righty's Cardinals debut Sunday.
Orioles: Showalter faces tough call
Before Saturday's game, Baltimore will have to make a personnel change as Ubaldo Jimenez is activated from the disabled list.
The Orioles' rotation has heated up lately, and the bullpen has been consistent all year. But one pitcher will be sent to the Minors to make room for Jimenez.
"These guys have made it hard on us," Showalter said, "and that's a good thing."
Showalter said Friday that he has a move in mind, but he wasn't ready to reveal it quite yet.
• Despite the month-long absence, Ubaldo Jimenez is still the American League leader in walks issued.
• After Friday night's loss, the Cardinals are now 7-11 in Interleague play this season. This is their final series against an American League opponent.
Matt Slovin is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.