BOSTON — The cheers were louder than the boos for Red Sox utility outfielder Wily Mo Pena last night. You’d think that would be a good thing. But not in this case.

Pena had a difficult night at the plate (0-for-3), and was especially hindered in the field, making an error that allowed the Blue Jays to score their seventh run of the game on a routine line drive to shallow center field in the sixth inning.

“He just missed it,” said Red Sox manager Terry Francona.

Pena said after the game the ball was dropping quickly and he did the best he could. In the seventh, he caught a routine fly ball, to the pleasure of the 37,161 fans in attendance, some of whom mocked him with the loud ovation.

“He’ll be all right,” said Francona. “They did that to him last year and he ended up being okay.”

Of course, Red Sox fans haven’t forgotten the trade Boston made to acquire Pena from Cincinnati for pitcher Bronson Arroyo, a fan favorite in this town. Because of that, Pena will forever be under the microscope, and when he has a difficult night or season, he’s going to hear the boo-birds.

“I’ve been there before,” Pena said of the fans’ reaction. “It’s all baseball here.”

Having a competent fourth outfielder on the bench in the majors is crucial. Pena certainly has the power to hit the long ball, but his defense is below average.

The Red Sox have David Murphy in Pawtucket, and the 25-year-old outfielder has proven he can play all three positions well, while also adding a solid bat off the bench. Pena, however, isn’t going anywhere, and he needs to play a lot more in order to get into a rhythm, which isn’t likely to happen in Boston.

“You can’t foresee someone dropping a fly ball,” said Francona. “Those things happen; they’re human. I don’t know if that has anything to do with playing time or lack of playing time. He just missed it.”

At the plate, Pena is 3-for-21 this season, with one home run.

A record crowd

While the Red Sox would like to forget about last night, the contest will be memorable in one way: It drew the biggest crowd since World War II.

Records were expected to be broken with the addition of more seats this year. Still, it was not until last night that official attendance went over the 37,000 mark — 37,161, to be exact — the 317th sellout since May 15, 2003.

Red Sox officials did not explain why the number was higher than any game in the Yankees series or any other contest this season. However, one explanation is that night games allow for bigger crowds than day contests since all of the seats in the bleachers in center are sold, while they are not during the day so that hitters won’t have trouble with the background.

Also, on Opening Day and in the Yankee series, it is likely more tickets were given away than for this series.

Recalling the crowd numbers will be better than remembering what happened in the game for the Sox. Boston made four errors, the first time the team has done that in a game since Sept. 9, 2005, at New York.

“It was just one one of those games; we didn’t play good defense,” said Eric Hinske, who made one of the errors. “You forget about it and move on.”

Reason was twofold

There were two pieces of news for Kevin Youkilis yesterday, and he wasn’t overly thrilled with either one.

One was that the Sox’ first baseman was being given a night off.

“It’s a good night. Youk ran into about every wall there is (Monday night),” said Francona.

Youkilis twice ran into fences chasing foul balls. That came on the heels of twice being hit by pitches.

“I think they added a triangle pad or something,” he said. “I thought I had about two feet of room, but it’s at an angle. When you’re running you think you have more room. That thing just jumped out of nowhere.” Despite the bumps, Youkilis said he was ready to play. He reported that he had just completed his usual pregame routine, including doing some weightlifting. Still, Francona felt it was a good time to give him some rest and equally importantly get Eric Hinske some work. Hinske hit in the number two hole usually occupied by Youkilis.

“He’s done such a good job staying prepared,” Francona said of Hinske. “He’s not playing enough for our liking, but I don’t know what else to do.”

The second issue with Youkilis was the All-Star ballot. Voting began this week. Youkilis is the only Sox regular not on the ballot. It is the second year in a row he is not on the ballot, but for good reason. Each team can have only one player at each position, and David Ortiz is listed as Boston’s first baseman.

“I don’t worry about that,” Youkilis said. “That’s out of my control.”

Slow going

Pitcher Matt Clement remains in Fort Myers as he continues to rehab his surgically repaired right shoulder.

The veteran right-hander had an arthroscopic procedure performed last September and, according to Francona, is still a long way off.

The two have been in contact via text messages over the last few weeks and Clement is playing long toss at 105 feet.

Defensive heroics

Mike Timlin saved his own life on Monday night. Toronto’s Gregg Zaun smoked a line drive right back up the middle that, fortunately, Timlin was able to snare. If the Red Sox reliever hadn’t been able to snare it, it possibly could have been a serious situation.

“Lucky stab,” he said after Monday’s game. “Either I caught it or it caught me . . . You just hope it doesn’t catch flesh. Usually the flesh is from the neck up.”

Timlin was able to joke about it, but the Red Sox have had some issues with their pitchers getting hit by line drives.

Case in point: Bryce Florie suffered serious facial injuries when he was hit by a line drive off the bat of the New York Yankees’ Ryan Thompson on Sept. 8, 2000, at Fenway Park. Florie was never the same after that. Most recently, Clement was drilled on the side of the head on July 26, 2005, in Tampa Bay.

Former Red Sox farmhand Josh Hancock had his jaw shattered on June 3, 2002, while pitching for Double-A Trenton.

Hall of Fame-bound

The bat used by Jason Varitek to hit the Red Sox’ fourth consecutive home run in the third inning Sunday night has been donated to the National Baseball Hall of Fame in Cooperstown, N.Y.

pkenyon@projo.com