CHICAGO -- Shortstop Javier Báez was kept out of the Cubs' starting lineup on Monday after being removed from Sunday night's 6-5 victory over the Nationals with a right heel contusion. Baez appeared to turn his ankle while fielding a ground ball in the third inning but stayed in the game.

Cubs manager Joe Maddon said he was planning on resting Baez one day this week but when Baez, 26, was still experiencing soreness on Monday morning, Maddon chose to start Addison Russell instead. Maddon said Baez was available to hit Monday against the Phillies if needed but might just get the night off.

"We'll do the day by day thing with him, but I think he's going to be fine," Maddon said.

Russell made his first start at shortstop this season in place of Baez, who had started all 44 games for the Cubs while hitting .319/.359/.595 with 11 homers and 31 RBIs.

Leading man
As often as Maddon has a tendency to juggle his lineup, Kyle Schwarber has established a comfort zone hitting leadoff.

While the Cubs' left fielder has traditionally hit further down in the order, he has found a way to produce at the top. Schwarber, who was the first Cubs hitter to face former teammate Jake Arrieta in Monday's game against the Phillies, entered the game with 34 career hits in the leadoff spot with eight home runs, eight doubles and 22 RBIs.

"I'm just going up there having competitive at-bats and not changing my mindset at all," Schwarber said before Monday's game. "I'm not going up there trying to walk -- I'm just trying to go up there and have the same at-bats [I would] if I was in the five-, six-, seven-hole, and go from there."

Schwarber was hitting .225 with six home runs and 15 RBIs overall, but .231 with one homer and four RBIs in the four games Maddon had placed him at the top. And while the expectation for the leadoff hitter is to set the tone for those who follow, Schwarber -- who had five strikeouts and four walks in 13 at-bats -- doesn't feel any additional pressure when Maddon bats him first.

"I think for me, I want to be selective and aggressive at the same time," Schwarber said. "I think walks just come and are just a product of the approach I have up at the plate. I'm not going to give into pitches early on -- I'm going to try to get mine. I think it's a good approach."

Injury updates
• Reliever Pedro Strop (hamstring) threw a 25-pitch bullpen session on Monday, according to Cubs president Theo Epstein, who said the session went well and that Strop will likely throw another later this week.

• Fellow reliever Brandon Morrow, who has been out since undergoing right elbow surgery in November, threw for the first time on Monday. Maddon said the next step for Morrow would be to begin a throwing progression.

• Minor League shortstop Nico Hoerner (Double-A Tennessee) was diagnosed with a hairline fracture in his wrist. Epstein said Hoerner -- ranked as the Cubs' top prospect by MLB Pipeline -- will be in a splint for three weeks and will likely miss at least a month.