Early this season, with the Prince William Cannons trailing 5-1 in the ninth inning, a runner tried to go from first to third on an infield out and was doubled up, ending the game. No matter how frustrating, that did not come close to Cannons Manager Dave Huppert's most trying night at the ballpark.

Huppert caught 31 innings for Rochester 15 years ago, when the International League Red Wings and Pawtucket played the longest game in professional baseball history. It was suspended after 32 innings, with Pawtucket winning in the 33rd two months later, 3-2.

"They pinch-hit for me in the 32nd inning, then I couldn't play when they resumed, because I'd already been in the game," Huppert recalled. "I might as well have finished it. Actually, I was well rested; I hadn't played in a week because of a hyperextended knee. After it got going, you just forgot about everything and kept playing."

Huppert almost became a hero in the 21st inning, rapping an RBI double to right-center. But Pawtucket scored in the bottom of the 21st to keep it going.

"That was my first year in Triple-A, so it was a big thing for me," Huppert said. "And as you repeat things, sometimes it gets even bigger as history. The worst part of it, the other catcher pulled a rib-cage muscle, so {Manager} Doc Edwards put me in the next afternoon, on Easter Sunday, and I caught nine more innings. Forty innings in less than 24 hours."

That's catching, folks. Sure, Cal Ripken played all 33 innings for Rochester, but he wasn't hunched down behind the plate. Choice Promotion

Once during each game, the Trenton Thunder of the Eastern League sends someone through the stands to select a fan to play "pick a gift." The fan must choose, unseen, either what the club official is carrying in a box or on his person.

On Mother's Day, the mother selected to compete opted for the contents of the box. After being told she had passed up a three-day all-expenses paid trip to Boston, she learned she had won a can of Spam. Happy Mother's Day! Never a Lock

One of the reasons for the Frederick Keys' sub-.500 status is their difficulty in finding a dependable closer. The Keys' bullpen has recorded 10 saves, spread among seven pitchers; none has more than two. Dark Side

The Keys' only midweek afternoon game of the season was a flop, as only 1,075 turned out. The experiment is unlikely to be repeated, although General Manager Joe Preseren conceded the testing was limited.

"It's the only one, so it's not a fair test," Preseren said. "But we can't afford to schedule 10 of them to really give it a try." Cheep Idea

A family of birds has nested in the Frederick press box, prompting one dim birder to suggest that the chirping intruders be exterminated.

"We can't kill the birds," public relations director Ernie Stepoulos said. "We're an Orioles farm club." Key Performer

Right-handed pitcher Chris Fussell of the Keys, who marked his 20th birthday Sunday, was given a present from Baseball America. He was selected Carolina League pitcher of the week for May 9-15, after throwing a five-hit shutout in Winston-Salem. Fussell was rated the Orioles' No. 4 prospect before the season began. 1-2-3 the Hard Way

Right-handed pitcher Calvin Maduro of the Bowie Baysox recorded an error, a putout and three assists while facing only three batters in a game at Harrisburg.

The leadoff batter bunted and took second on Maduro's throwing error. The next batter also bunted and Maduro got the runner in a rundown, eventually tagging him out while the batter reached second. Maduro then picked him off. The next batter doubled and Maduro, backing up a wild throw to second base, threw him out at third. He's a Homer

Outfielder Kevin Curtis of the Baysox bats right-handed, so it is not too surprising to learn that through Tuesday he is hitting .308 against left-handers, only .207 against right-handers. Curtis has another statistic that borders on the unbelievable, however. He is batting .338 at Prince George's Stadium, just .109 on the road. Upcoming Series

Tonight through Thursday, Canton-Akron at Bowie; Thursday through Sunday, Durham at Frederick, Salem at Prince William; Monday through May 30, Portland at Bowie; Monday through May 29, Lynchburg at Frederick. Upcoming Promotions

Thursday, Myron Noodleman at Frederick; Saturday, fireworks at Prince William; Saturday and Sunday, Country Western Weekend at Frederick; Sunday, oven mitts at Prince William; Monday, fireworks at Frederick.