PAWTUCKET — There were two examples Tuesday night of how carefully the Red Sox organization attempts to deal with pitching prospects.

Kris Johnson and Clay Buchholz were the pitchers involved.

Johnson, making his first appearance since May 31, got the start in the opener of the McCoy doubleheader, but was allowed to throw only 74 pitches. He had been transferred to the Lowell roster June 1.

"He didn't get shut down by any injury," manager Ron Johnson said of the lanky lefty. "From an organizational standpoint, they've done this with almost everybody. … You get to a certain time of the year and they give almost everybody a little blow."

The plan had been to sit Johnson for 11 or 12 days to give him some rest. However, he had some minor back problems, so the team extended the time off for several more days.

The rest helped Johnson. After getting off to an excellent start — he did not allow a run in his first two starts — he had been struggling. In his return, he went 4 1/3 shutout innings, allowed two hits, walked three and struck out five. But it was not enough as Charlotte won, 1-0, in eight innings on a home run by Josh Kroeger.

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Clay Buchholz was involved because he did not pitch. The Sox want to make sure he is well rested.

Buchholz, who has been outstanding all season, was scheduled to pitch Monday night. He had gone through about half his normal pre-game throwing when the rain came. The game was eventually postponed.

In the majors, a pitcher who went through the same situation likely would have been able to pitch if the game had resumed. Almost certainly, he would have been used for one of the two games Tuesday.

But the Sox held Buchholz back an additional day to be safe. He will pitch Wednesday, although he will not start. John Smoltz, whose debut with Boston has been pushed back, will start and pitch three innings, then Buchholz will come on in relief.

"It's different than the big leagues," Johnson explained. "Our focus is more of the individual performance of the player and his development. In the majors you've got to win that game."

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The designated hitter has not been hitting for Pawtucket this season.

DH Paul McAnulty was ejected in the fifth inning of the opener. He complained about being called out on strikes to end the fourth. McAnulty was 0-for-2 and Jeff Natale, who replaced him, was 0-for-1.

Their problems continued a bad season for the PawSox' designated hitter. The players used as the DH have hit 48-for-235, a .204 average, with eight home runs.

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Justin Cassel, brother of former Patriots' quarterback Matt Cassel, pitches for Charlotte Thursday in the series finale. It also will be Pink Out Night, to promote breast cancer awareness. … Buddy Bell, the former major-leaguer who is now the player development director for the White Sox, took in the doubleheader. … Armed Forces Night was observed between games Tuesday night.

pkenyon @projo.com