A major sports rivalry comes to Busch Stadium on Thursday - but it doesn't involve the Cubs, or the Brewers, or baseball at all.

The exhibition game between Manchester City and Chelsea of the English Premier League will be the first time that the stadium locals sometimes call "Baseball Heaven" hosts a sporting event other than baseball since it opened in 2006.

Here's how you convert a baseball diamond to a soccer pitch.

"Oh boy."

That was the first though that registered in Bill Findley's head when he was given the task of getting Busch Stadium ready to host two of the world's top soccer teams.

Findley is the head groundskeeper at Busch, which puts him in charge of making sure the grass is green, the Arch in center field is perfectly mowed, the foul lines are straight and the base paths are well-packed.

But he'll have to undo most of that hard work by Wednesday night, when Chelsea and Manchester City take the field for a practice session before Thursday's game.

"Obviously, it's very stressful for me and my crew," Findley says. "We want to make sure that we're giving the best possible playing surface to the baseball team. As a groundskeeper, I have to roll with the punches, so to speak."

How it's done

When it comes to putting a regulation-sized soccer pitch into a baseball stadium, there's a lot of potential for knock-out blows. (In fact, the pitch at Busch will be slightly smaller than the dimensions required by soccer's international governing body, but there's some leeway for an exhibition match).

Findley and a crew of about 20 will have three working days - Monday, Tuesday and Wednesday - to make final measurements, dig out the infield dirt - including the pitcher's mound - lay sod, and paint the actual pitch.

(Rachel Lippmann/St. Louis Public Radio)

"We can sod in our sleep," Findley says of his crew. "Putting the actual grass in the dirt areas, that's going to be the easy part. The hard part is going to be getting the dirt out without wrecking the field in the process."

Just before 11 a.m. Monday, crews with shovels and rakes are making their way around the field scraping loose dirt into a conveyor belt that blows it into the back of a utility cart. Nearby, a backhoe is demolishing the pitcher's mound. Another groundskeeper begins breaking up the dirt on the third base line.

Jason Griffin, the head groundskeeper for Chelsea, is keeping a watchful eye on the process, and likes what he sees so far.

"This isn't new to us," he says of playing in baseball stadiums. "But the process that they're doing out here is a new way of doing it. It's very good. It's going to be nice and flat, which is what both teams want."

The new normal

A scene like this will become more and more common at Busch and throughout the major leagues, says Joe Abernathy, the stadium's vice president of operations.

"As any company is these days, you're trying to maximize your revenues," Abernathy says. "We've got a tremendous asset here at Busch Stadium, which holds 45,000 people. It's a great location here in downtown. We're challenged to see how we can take advantage of that asset on non-game days. We only have 81 games a year."

Abernathy says timing is the most important factor when it comes to scheduling a special event like Manchester City-Chelsea. A 7 to 10 day window is the best, especially earlier in the season when it's not as hot and it's easier to do any repairs to the field.

The organization, says Abernathy, was always excited about the possibility of soccer matches at Busch. Efforts to get a soccer match in the fall didn't come together, but the operations and special events staff found a window in May.

"It's a low-impact sort of of an event on the field, as opposed to a concert where we're covering the stadium with some type of field covering and then putting seats and stages out there," he says.

Groundskeeper Bill Findley says aside from being new, the conversion to a soccer pitch isn't the most stressful special event he's dealt with.

"It was definitely the U2 concert," he said. "Having to re-sod the whole field in the middle of July after a concert, then playing on the field three days later, two days later, and then having to go the rest of the season with that fresh sod that we put on the field in July."

Setting up for the future

Findley and Abernathy know that people will be watching to see how well the crew can make the switch from baseball to soccer and back to baseball on a tight timetable. European teams, says Abernathy, are doing more traveling. A successful exhibition opens up the possibility of getting other field sports, like lacrosse.

(Rachel Lippmann/St. Louis Public Radio)

And because Major League Baseball doesn't take a percentage of the ticket sales as they do with Cardinals games, special events mean more revenue for the team.

Head groundskeeper Bill Findley says that's why he's willing to take one for the team and dig up those perfectly groomed basepaths.

"I signed up to be a baseball groundskeeper, so you'd rather just be doing baseball, but you know, I work for the Cardinals, I work for the organization, and this is how I help the organization - by making these events happen," he says.

And even if the forecasted rain leads to long hours, he says Manchester City and Chelsea will have a field by Wednesday night.

Follow Rachel Lippmann on Twitter: @rlippmann