Pettitte hurled five scoreless innings for Single-A Tampa last night in Sarasota, striking out eight. The strongest part of the best team in baseball is about to add more muscle.

If Andy Pettitte doesn’t experience any problems with his left elbow and right ankle today, the winningest AL pitcher across the last three seasons (55 victories) isexpected to start Saturday against the Tigers in Detroit.

Pettitte, who has been shelved since March 7 when he complained of a stiff elbow after one inning of work against the Twins, hurled five scoreless innings for Tampa (Single-A) last night in Sarasota. He allowed four hits, walked two and fanned eight. Of the 81 pitches Pettitte threw, 53 were for strikes.

“I feel like I am ready,” said Pettitte, whose fastball was clocked at 89 mph. “I felt good with everything and that was really what I was looking for.”

Organizational pitching guru Billy Connors saw no reason why Pettitte can’t make his initial start Saturday for the Yankees, who will be needing a fifth starter for the first time this year.

“My recommendation is that he would be ready,” Connors said. “His pitches were real crisp.”

What the Yankees will do to make room for Pettitte isn’t immediately known and doesn’t have to be done until Saturday. One option is letting third-string catcher Mike Figga go. Another is staying with 10 pitchers and sending Jason Grimsley or Dan Naulty to Columbus (Triple-A).

Pettitte, who sprained his ankle on April 6 running backward during an agility drill, gave up an opposite-field double to Red Sox first baseman Reggie Jefferson in the fourth after striking him out in the first. Jefferson is on an injury rehabilitation assignment.

Until last night, Pettitte had worked just 82/3 innings of minor league and simulated games since March 7.