ST. LOUIS — Skipping Michael Wacha's start Sunday is the St. Louis Cardinals' way of protecting their young right-hander.
And manager Mike Matheny explained Friday that it won't be the last time Wacha (5-5, 2.79 ERA) is bypassed.
"We're guarded because we're cautious. We're guarded because we look at the number of innings we have to keep on top of," said Matheny, noting Wacha's 90 1/3 innings and the fact that the Cardinals leaned hard on him in the postseason last year.
"Even though he had a good start his last (time) out, he's still a young pitcher getting used to this every-fifth-day thing," Matheny said. "It's a grind. We'll continue to watch him and take those days whenever we can. This isn't going to be the last time; it's going to happen again. We knew at the beginning we were going to do it. Timing was more than anything else."
Rookie Carlos Martinez (0-3, 4.19 ERA) will start for Wacha. Martinez replaced Adam Wainwright (elbow tendinitis) in the rotation Monday and threw four innings and 59 pitches against the New York Mets, getting no decision.
"I think we have to watch how it all plays out," Matheny said. "There's not this master plan of, 'OK, the next guy that's going to get skipped is this guy.' That's not where we are. It worked out well, with what we were seeing from Michael and watching him work pretty hard. And once again, realizing that he needed that time throughout the season. The timing was right more than anything."
Wainwright leads the rotation with 100 1/3 innings, followed by Lance Lynn (91 1/3), Shelby Miller (91) and Wacha.
Megill shuns Cardinals
Right-handed pitcher Trevor Megill, the Cardinals' third-round pick (104th overall) in the amateur draft, has opted to return to Loyola Marymount for his senior season.
The 6-foot-8, 235-pounder, from Huntington Beach, Calif., missed this season as he recovered from Tommy John surgery.
Cardinals General Manager John Mozeliak said the team no longer will scout Megill, adding that Megill wanted more than the designated slot value of $504,400.
"We were basically instructed not to make any offers, so we didn't," Mozeliak said. "Ultimately, he chose to go back to school."
Mozeliak said the Cardinals didn't try to sway Megill.
"Never beg somebody to play. It's pretty simple," Mozeliak said. "We'll redeploy."
The Cardinals lose the $504,400 from their pool of draft money, but will receive an extra pick at the end of the third round in 2015.
Reliever Kevin Siegrist played catch from about 120 feet Friday and felt only mild discomfort in his left forearm. Siegrist has been on the disabled list since May 24.
"It's just retraining that nerve so I can throw again," he said. "I'm just taking it day by day based on how I feel."
When he will be activated, Siegrist said, "is not my call."
"I just want to make sure I'm 100 percent before I go back out there," he said. "I still felt a little (discomfort), but it's progress, definitely."
Siegrist said there's a possibility he will throw a bullpen outing Sunday before the final game of the Cardinals' homestand.
Another injured pitcher, Joe Kelly, is expected to throw what Mozeliak called a "rigorous bullpen" Sunday.
"Then it's a baseball decision after that," Mozeliak said of when Kelly might begin a rehab assignment.
Promotion for Gonzales?
Mozeliak said left-hander Marco Gonzales, the Cardinals' first-round pick (19th overall) in the draft last year, could be in line for another promotion before the end of the summer.
Gonzales was 2-2 with a 1.43 ERA in six starts for Palm Beach of the high-Class A Florida State League. He was elevated in mid-May to Class AA Springfield of the Texas League in mid-May, and is 3-2 with a 2.33 ERA in seven starts at Springfield.
"We had high expectations of Marco," Mozeliak said. "The last three or four weeks, he's performed at a very high level for that league. It gives us hope that he could end up at Triple-A before the season ends, so that's very encouraging."
St. Louis had just two homestands in the first month and a half of the season, playing 26 of its first 38 games away from Busch Stadium. It's only a memory now, however.
"I think we're beyond what the obvious was. The obvious was it was lopsided early," Matheny said. "You're trying to get your feet settled, especially the new guys who have never been here before. You wanted them to get used to being at home, but we just weren't here very often."
Friday marked the Cardinals' 38th home game; they have played 36 road contests.