Being a middle infielder for the Portland Sea Dogs has proven to be hazardous duty.

The Sea Dogs lost their starting shortstop and second baseman, Nelson Castro and Carlos Leon, in the first two weeks of the season.

Since then, utility man Raul Nieves has also landed on the disabled while replacements Tony Schrager and Jim Goelz have been hobbled.

Leon was injured in the home opener against the Binghamton Mets when Daniel Garcia slid hard into second base trying to break up a double play.

Sea Dogs manager Ron Johnson took him out of the game as a precaution, thinking the injury was minor.

Two days later Leon was diagnosed with a fractured left fibula.

“I was surprised,” Leon said of the diagnosis. “It hurt, but I didn’t think it was that bad.”

Leon was placed on the disabled list and sent to the Red Sox’s complex in Fort Myers, Fla., to begin rehabilitation.

He returned to the Sea Dogs’ line-up June 1, more out of necessity than anything else, when Nieves went on the DL with a broken bone in his foot.

Despite missing 46 games and having played in only a pair of simulated games in Fort Myers, Leon didn’t miss a beat.

He had a hit in seven straight games and went 10-for-24 (.417) over that stretch.

“That’s a good thing for him because he’s a guy who I think can be a useful guy in a utility role at the major league level,” said Johnson, who managed Leon at both Class-A Sarasota and Double-A Trenton. “Guys like that don’t play every day, not that he can’t. But he’s shown that he can sit and come right out and produce.”

Although he was solid at the plate, the hasty return left Leon a little bit tentative on the basepaths.

“I was worried about hurting it again,” Leon admitted.

The leg is almost up to full speed but Leon strained his hamstring on June 21 in New Haven and has been in and out of the line-up ever since.

Leon is no stranger to injuries, having missed most of the 2001 season with ligament damage in his wrist.

After suffering through a dismal season last year with last-placed Trenton, Leon is hoping to stay healthy enough to enjoy the success the Sea Dogs are having.

“It’s been a lot of fun,” said Leon. “This team’s more together. Everybody pulls for each other.”

Taking one for the team

Johnson jokingly labeled John Nathans “the hardest working catcher in baseball” when the Sea Dogs’ reserve backstop sprinted out to the bullpen to warm up pitchers in between at-bats during a game earlier this season.

Nathans took hustle and grit to a whole new level during Tuesday night’s doubleheader in Harrisburg, catching the second game of the twin bill with a slightly separated shoulder.

“The guy’s one of the most gutsy players I’ve ever been associated with,” said Johnson. “There are gamers and then there are guys who will do whatever it takes. This guy never even hesitated.”

Nathans injured the shoulder sliding into second base in

the first game of the doubleheader.

Also in that game, regular catcher Kelly Shoppach was injured in a home plate collision with the Senators’ Jeremy Ware.

Shoppach finished the game, but was unable to play in the nightcap.

“I had a little floater running across my eye for a couple of hours,” said Shoppach.

With the injuries piling up, Johnson had only one other option behind the plate.

“Charlie Weatherby,” Johnson said of his pitcher. “He came up to me and told me he had caught in high school. I said, ‘Chuck, I don’t think the front office is really going to like that.'”

It took Harrisburg a couple of innings to realize Nathans couldn’t throw.

“A base hit was a triple and there was nothing I could do about it,” said Nathans. “I could throw the ball like a dart, but that was it.”

The Senators stole seven bases, but were held to just one-hit by three pitchers. Nathans went 2-for-3 and the Sea Dogs won 5-3.

The next day, he was put on the disabled list.

“It was a little separated,” he said. “I just popped it back in.”

Help on the way

A number of the injured Sea Dogs will likely return this week.

Junior Herndon threw pain-free in the bullpen Friday and will start Monday night against New Britain.

Herndon (5-3, 4.92 ERA) has been sidelined with a pulled groin muscle since June 17.

Outfielder Kevin Haverbusch is eligible to come off the DL on Monday. He hasn’t played since June 14 in Akron.

Pitchers Eric Glaser (sore triceps) and Jake Chapman (strained muscle in side) are also close to being activated.

Future star

Fans at Hadlock Field will get a chance to see one of the top prospects in baseball when catcher Joe Mauer comes to town with New Britain for a four-games series beginning Monday night.

The Minnesota Twins selected Mauer with the first overall pick in 2001 draft.

He has hit .321 in 15 games for New Britain since being called up from Class-A Fort Myers on June 16.

Mauer a three-sport star at Cretin-Derham Hall in St. Paul, Minn., averaged almost

20 points per game on the basketball court in addition to being a highly recruited quarterback.

But a $5.15 million signing bonus was enough to persuade Mauer to not accept a football scholarship from Florida State.

No Giambi

Don’t look for Jeremy Giambi to join the list of Red Sox who have rehabbed with the Sea Dogs.

Giambi was sent to Triple-A Pawtucket, where he’ll remain until July 11.

Bill Foley is assistant sports editor. He can be reached by e-mail at [email protected]