WASHINGTON -- Just a few short days ago, when the White Sox took three of four from Cleveland to surge into second place in the AL Central, it seemed as if Chicago was putting the pieces together and perhaps playing ahead of the expectations set for this ongoing rebuild. But

WASHINGTON -- Just a few short days ago, when the White Sox took three of four from Cleveland to surge into second place in the AL Central, it seemed as if Chicago was putting the pieces together and perhaps playing ahead of the expectations set for this ongoing rebuild.

But if two games at Nationals Park proved anything, it’s that the White Sox still have plenty of growing pains to comb through. In Wednesday’s 6-4 walk-off loss to the Nationals, Chicago made three errors -- two of which either kept the Nationals’ line moving or directly resulted in a run for D.C. -- and squandered several chances in the ninth inning before the Nationals’ final blow.

“We didn't help ourselves,” manager Rick Renteria said. “We dropped a fly ball. We had a couple plays today -- we got doubled off at third; we had a fly ball that was dropped; that wasn't a very good bunt in the last inning.”

After an error by Yolmer Sánchez helped the Nationals eventually push across a run in the fourth, Tim Anderson could not make the catch on a tough popup in shallow left-center that allowed Gerardo Parra to cross home and make it 4-1.

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When the White Sox fought back to tie things up in the eighth, a misplaced bunt from Ryan Cordell stymied Chicago’s momentum, and back-to-back strikeouts by Sean Doolittle stranded a pair in the ninth.

“There were a lot of things we can critique,” Renteria said.

And that’s part of some of the more encouraging reassurances for Renteria and his staff. Some of these mistakes are easily visible, changeable with practice and hopefully resolvable as the younger White Sox squad continues to gain experience trudging deeper into the 2019 season.

And Chicago is also encouraged by the fight its club showed in Wednesday’s matinee. As Dylan Covey turned in another decent start -- two earned runs using 77 pitches in five innings -- the White Sox were able to climb back from the 4-1 deficit with back-to-back eighth-inning homers from Jose Abreu and Welington Castillo in the latter’s first start since returning from a concussion.

“Today we did everything to counter some of the things that didn't go well, and we put ourselves actually in a good position,” Renteria said. “We just weren't able to get it done."

For Covey, it continued a string of four consecutive outings going at least five innings, dropping his ERA from 5.64 to 4.58 in the process -- albeit after an outing Wednesday in which he admits he did not feel 100 percent.

“Just don’t feel like I got loose … that every pitch I was throwing was like the first one I was throwing of the day,” Covey said. “But it’s a good sign for me that I'm able to have an outing like that when I don’t feel great.”

His manager agreed with the sentiment: “I got everything out of Covey today that I could have possibly gotten out of Covey today,” Renteria said. “I couldn't have gotten more out of him, and I'll leave it at that.”

The White Sox showed encouraging flashes of the resiliency that recently got them back within a game of .500, undone only by an uncharacteristic outing from Alex Colomé. A four-pitch walk to Brian Dozier was further exacerbated by Trea Turner, who sent a high 95 mph fastball 399 feet to left-center, sinking Chicago back to three games under .500.

“I just missed that pitch. I pitched high today,” Colomé said. “Missed one pitch they're looking for, and they got it in that situation.”

Encouragement in this case comes from the belief that this was just a blip on the radar for the 30-year old reliever in the midst of a career year.

“You can't say much about Colomé, this guy is the best.” Renteria said. “He just left one up."

Still, it does not help mend the temporary sting of falling further from .500 and dropping out of second place in the Central. Three games in last-place Kansas City to try and flip a 2-7 record in the past nine road games might help, though.