In 2012 -- especially recently -- that sinker seems to have baffled Morton more than opposing batters.
When the Pirates host the Astros on Saturday in the second game of a three-game series, Morton will find out if the sideline work he's put in with the sinker pays off. He has allowed three homers to righties in his last seven innings and four overall this season.
His home run total against righties over 171 2/3 innings in 2011: one.
"I have to take a step back and find that good sinker," Morton said. "I know I can keep the ball in the park, and on the ground. That's where I need to be. I have to look at it objectively and do something -- mental or physical -- to get the breaking ball back. The sinker is all I am."
Morton (1-3, 4.61 ERA) will face a Houston lineup that is quietly turning a few heads with marked improvement from a woeful 2011 season.
"Our hitting coach, Mike Barnett, has done a terrific job with that," first-year general manager Jeff Luhnow said. "Guys have responded, and I think part of it is an education process of realizing how important seeing good pitches is to having a productive offensive unit. Part of that is laying off bad pitches."
Following a 1-0 victory over the Bucs on Friday, the Astros sit two games below .500, with 10 of their 17 losses having been decided by two runs or fewer. They send lefty J.A. Happ to the mound on Saturday.
Happ is 2-2 this year with a 5.24 ERA, and those numbers essentially describe his season. He has been inconsistent for the Astros, who have won three of his six starts.
Happ allowed four walks and two homers, tying his season highs in both categories, in his start last Sunday against the Cardinals.
Astros: Altuve to three-hole
In the wake of J.D. Martinez's 0-for-21 slump, second baseman Jose Altuve moved to the third spot in the order on Friday, and it's likely he'll remain there for the full series.
"I was going over some stuff on the plane last night and was kind of looking at some things and looking at this ballpark and so forth," Astros manager Brad Mills said. "There were a lot of things I liked about [batting Altuve third]. I'll keep those to myself, but there were a lot of things I liked about it."
Altuve's .325 batting average is the highest in the Major Leagues among second basemen.
Carlos Lee has been one of the toughest hitters to strike out this season, averaging one strikeout every 15.25 plate appearances. He has struck out just eight times this year and has 12 walks.
Closer Brett Myers has not blown a save in nine chances.
Pirates: Presley slumping
Outfielder Alex Presley, one of the Bucs' most productive hitters early in the season, has been mired in a 3-for-33 slump since April 29. As a result, he's seen a steady decrease in playing time.
"The hardest part is being in and out, because ... it's hard to get into a flow, the timing," Presley said. "The best way of getting into a rhythm is by being in games. It hasn't been the easiest thing not being in there."
Presley's average has dropped to .239. He has two homers and seven RBIs.
Outfielder Jose Tabata is hitting .308 in his last 16 games, and he has hit safely in 13 of them.
The Pirates are 9-0 this season when they have the lead after six innings.
In both of his starts this month, Morton has taken the loss, allowing a total of 11 runs (nine earned) in 10 1/3 innings.
The Pirates have won each of the last five series between the two teams at PNC Park. Houston would break that streak with a win on Saturday.