PHILADELPHIA -- Both Chris Paddack and Fernando Tatis Jr. have had their names come up plenty in this season’s National League Rookie of the Year Award discussion. Friday, however, may have marked the end of that pursuit for the Padres' pair of star rookies.

On the same day that the club announced Tatis would likely miss the rest of the season, Paddack was tagged for five runs (four earned) on nine hits in just 4 2/3 innings in an 8-4 loss to the Phillies at Citizens Bank Park.

• Box score

So while Tatis' NL Rookie of the Year Award candidacy all but ended with Friday afternoon’s revelation, Paddack's quest for the honor took a major hit just hours later.

It certainly didn't seem that would be the case early for Paddack, as the 23-year-old righty showcased his potential in the first inning. Paddack struck out the side on just 11 pitches, while inducing six swings and misses, including three by Bryce Harper. The Phillies’ slugger whiffed at a pair of 94 mph fastballs then laid off a 95 mph heater above the zone, only to chase a curveball below the knees on the following pitch.

"Like a lot of times, you see him come out with a really live fastball, really attacking, really dominant," manager Andry Green said. "First inning, punches a guy out with the fastball, a curveball and a changeup -- looks like everything’s working right there."

As has been the case at times this year, however, Paddack may have simply thrown too many strikes.

He entered the night having thrown 70 percent of his pitches for strikes this season, the highest rate of any pitcher with at least 100 innings of work -- and the Phillies were ready for it. While Paddack forced 16 swings and misses -- his third most in any outing this season -- he also had 29 pitches fouled off. Paddack had only seven called strikes all night, four fewer than any of his previous 20 career outings.

In other words, if the pitch was in the zone, the Phillies were swinging.

"Those are things Chris is working on," Green said. "He’s very cognizant of when he gets those 0-2, 1-2 counts, he fills up the strike zone and he does it really, really well -- but there’s times you’re going to be successful outside the strike zone."

After breezing through the first inning, Paddack found himself in a jam after allowing back-to-back hits to put runners on second and third with only one out. He forced Scott Kingery to pop out, then quickly got an 0-2 count against Cesar Hernandez. Hernandez fouled off the next two pitches, both of which were in the zone, before lining an RBI single on a pitch just off the plate.

"I felt good coming out of the gates, thought it was going to be a good night," Paddack said. "Got through that first inning quickly, then I kind of hit a wall there. The second inning kind of sped up to me. I thought I could have done a better job of slowing the game down, reading their swings."

The problems mounted one inning later when Paddack allowed a solo homer to Roman Quinn on a fastball over the middle of the plate. Two batters later, J.T. Realmuto sent a hanging curve at the top of the zone into the seats in right-center field.

Friday marked the second time in his last three starts that Paddack was unable to complete five innings. He's allowed five homers over 14 2/3 innings during that span, and he has now served up 18 home runs in his last 14 starts after allowing only two in his first seven big league outings.

"When you look at it, if I keep them to three runs, we come out on top," Paddack said. "It’s just one of those things I’ve got to continue to learn from, how to not let the game speed up on me. Learn how to kind of be a bulldog when things hit the fan a little bit -- being able to limit that damage."

Paddack has a 7.98 ERA in three August starts after posting a 1.82 mark in his previous five outings that had brought his season ERA back down to 2.78. That overall number now sits at 3.44, the highest it's been all season.

"Overall, you love what he’s doing, you love his stuff," Green said. "More runs than you feel like he should be giving up, but that happens from time to time."