It's clear that the Miami Marlins are being careful with hard-throwing Jose Fernandez as he works his way back from Tommy John surgery.
The Arizona Diamondbacks' Robbie Ray is also known for his fastball, though the youngster is proving he is open to using the rest of his repertoire as well.
These talented youngsters will meet for the first time Wednesday night in the finale of a three-game set at Chase Field.
The 22-year-old Fernandez (2-0, 2.37 ERA) has made three starts since returning from Tommy John surgery, totaling 21 strikeouts against one walk. The right-hander was pulled after 70 pitches Friday and charged with two runs in six innings with six strikeouts in a 6-3 defeat at Philadelphia.
"I just tried to give my team a chance to win every time out, and I'm glad I'm healthy again," he said.
That outing marked his first road start. Fernandez is 7-1 with a 1.46 ERA in 11 career starts after the All-Star break.
The 23-year-old Ray (3-4, 2.29) has yielded two runs or fewer in seven of nine outings, including a five-inning stint Friday in which he gave up that many and struck out a career-best eight in a 6-5, 12-inning loss to San Francisco.
The left-hander threw 72 of 99 pitches for strikes, saying he is starting to not exclusively rely on his fastball, which averages 93.3 mph. He throws the fastball 73.0 percent of the time - 64.3 percent when he's ahead in the count and 83.1 when he's behind.
"I'm mixing in the slider and changeup more than I have and that was working for me as long as I was keeping it down in the zone," Ray said.
Ray has never faced the Marlins (39-55) or any of their hitters. Miami may be eager to face Ray since it is batting an NL-best .279 against left-handers. Shortstop Adeiny Hechavarria has a .386 average against southpaws to rank among baseball's best.
Fernandez's lone career outing against Arizona was a 3-1 defeat in which he gave up two runs in 7 1-3 innings in 2013.
Diamondbacks slugger Paul Goldschmidt went 0 for 3 against him in that contest as the two will meet again in what figures to be the game's most intriguing matchup. Goldschmidt is batting .341 to lead the league, with injured Miami leadoff hitter Dee Gordon second at .338.
Another well-pitched game figures to be on tap after these clubs split the first two games. Arizona (43-49) got seven strong innings from Rubby De La Rosa to win 3-1 on Monday before Miami ended slides of four straight and eight in a row on the road the next night as Mat Latos struck out seven in seven innings in a 3-0 victory.
Arizona center fielder A.J. Pollock went 2 for 4 on Tuesday and has reached base safely in 17 straight games. He is hitting .319 with 13 runs scored in that run.
Miami outfielder Christian Yelich is 4 for 8 in this series and 11 for 28 over a seven-game hitting streak.