Of course, in this season, nothing can be totally smooth: Giles hit a stumbling block Sunday in a 4-0 loss to Washington. Entering the game with a 0.87 ERA, he allowed three runs, two of which were earned, in just one-third of an inning.
"There is nothing I can do about it now," Giles said afterward. "I just have to forget about it and move on."
The Nationals had looked overmatched by Giles in Thursday's 10-4 loss to the Phillies as he struck out three in 11/3 innings of scoreless relief.
Giles entered that game with runners on the corners and two outs in the seventh inning, trying to protect a 7-4 lead.
He promptly ended the inning by striking out former Phillie Jayson Werth, who whiffed on a 100-m.p.h. fastball.
Giles said he didn't look at the scoreboard to check the speed of his pitch.
"No, I was too pumped that I was able to get the job done to keep the lead for the team," he said.
On Sunday, however, Washington made an adjustment. Werth had one of the key hits, a run-scoring double, on a 97-m.p.h. fastball.
"They learned from the past experience and I have to adjust my next outing," Giles said.
Giles allowed a home run in his first outing, pitching one-third of an inning in the 7-3 win over San Diego on June 12. In his next 18 appearances before Sunday, he had a 0.44 ERA.
Even with Sunday's setback, Giles has a 1.71 ERA in 20 appearances. In 21 innings, he has struck out 31 and walked six.
An improved slider has helped him. According to PITCHf/x data, opponents are hitting .129 against his slider.
Papelbon said Giles has impressed him with his approach to the game.
"It's hard to prepare every single day for a big-league game and what I have seen from him so far is that he goes about his business in a pretty good way," Papelbon said.
Giles, who turns 24 next month, had never pitched above single-A Clearwater before this year. Last season, he had a 6.31 ERA for Clearwater but also was hampered by an oblique injury that twice sent him to the disabled list.
"It was frustrating last year," Giles said of dealing with the injury. "I knew it was kind of a blessing in disguise and it gave me more time to work on mechanics and the mental game a little bit."
He was a non-roster invitee to spring training and wowed the Phillies early on with his fastball and improved slider. He had a 2.08 ERA in 41/3 spring-training innings, with five strikeouts.
Giles began the season at double-A Reading, where he had a 1.20 ERA, 29 strikeouts, five walks and seven saves in 15 innings. At triple-A Lehigh Valley, he had a 2.63 ERA with nine strikeouts, eight walks and five saves in 132/3 innings.
Manager Ryne Sandberg expects Giles to rebound from Sunday's outing.
"He really seems to be mature with his aggressive approach and it shouldn't be a problem," Sandberg said.
The 6-foot-2, 205-pound Giles concedes that he didn't envision such a rapid rise to the majors, but he hasn't been overwhelmed by his new surroundings.
"I didn't know if I would get here this quickly, but nothing is impossible," he said.