Philadelphia manager Gabe Kapler wasn't expecting to press outfielder Jay Bruce into action in his first day with the Phillies.

However, a day after Bruce was acquired from the Seattle Mariners, he found himself trotting out to left field in the bottom of the first inning after Philadelphia lost starting center fielder Andrew McCutchen in a freak play during the top of the first Monday night at San Diego.

Now things get interesting for the Phillies, who have seen their lead in the National League East slip to a half-game over the Atlanta Braves during a string of five straight losses.

McCutchen sustained a left knee strain as a victim of an unusual scenario. He had to be helped from the field after going down in pain near the first base bag after being tagged out in a rundown. Officially, the Phillies listed McCutchen as day-to-day with a knee sprain, but more medical exams are to come.

"We'll know more after an MRI (Tuesday)," Kapler said after the Phillies suffered through a seven-run Padres sixth inning and an 8-2 loss in the opener of a three-game series.

Bruce finished 1-for-3 in his Phillies debut. He had hit .212 with 14 homers and 28 RBIs in 47 games for Seattle this year.

On Tuesday night, the Phillies will send out right-hander Jerad Eickhoff (2-3, 4.10 ERA) to face Padres right-handed rookie sensation Chris Paddack (4-3, 2.40 ERA) in the middle game of the series.

Paddack, who has never faced the Phillies, is just 3 2/3 innings shy of qualifying for the No. 3 spot among National League ERA leaders, despite coming off one of the worst of his 10 major league starts Wednesday afternoon at Yankee Stadium.

Paddack gave up four runs -- three on solo homers -- on six hits and a walk with six strikeouts in just five innings against the New York Yankees.

On the season, opponents have hit .170 against Paddack with a 0.817 WHIP. He has allowed 34 hits and 12 walks with 62 strikeouts in 56 1/3 innings. That's a 5.2-to-1 strikeout-to-walk ratio and an average of 9.9 strikeouts per nine innings.

"We know what Chris can do," Padres manager Andy Green said. "He's performed brilliantly. Games like his last one are going to happen."

But over his past three starts, Paddack has given up five home runs (two to the Dodgers, three to the Yankees) in a span of 15 2/3 innings. Over those games, he has allowed 11 runs (eight earned) on 16 hits and two walks with 16 strikeouts for a 4.60 ERA and a 1.15 WHIP.

After his first seven starts, Paddack had a 1.55 ERA and had allowed only 18 hits in 40 2/3 innings.

Eickhoff will be making his 10th appearance and ninth start of the season Tuesday night. He has allowed 22 runs on 43 hits and 15 walks in with 43 strikeouts in 48 1/3 innings for an opponents' batting average of .242 and a 1.20 WHIP.

However, he has struggled over his past four starts, going 0-2 with a 8.35 ERA, a .329 OBA and a 1.58 WHIP.

Eickhoff hasn't face the Padres since 2017, but he has a 3-0 career record against them with a 1.96 ERA covering four starts. He has 27 strikeouts against four walks vs. San Diego in 23 innings with a 1.00 WHIP.

--Field Level Media