TAMPA — One of the biggest concerns voiced by Major League Baseball and the Tampa Bay Rays when they dismissed a Hillsborough County plan for an Ybor City ballpark this week was that there was no big-money private investor lined up to front the costs of the $892 million project.

Yet county leaders had said publicly they did have interested potential investors.

Behind the scenes, though, officials had concerns that one of those firms, Oak Street Real Estate Capital, is a client of Ron Christaldi, a prominent Tampa business lawyer who is heading up Rays 2020, an organized effort to drum up interest in corporate boxes, season tickets and naming rights in an Ybor stadium.

"There was a significant amount of concern from our outside counsel and (County Administrator ) Mike Merrill that there was either a conflict of interest or a perceived conflict of interest," said Hillsborough County Commissioner Ken Hagan, who has spearheaded efforts to move the Rays to Tampa.

A key part of the county's proposal hinged on getting much of the money needed to build a ballpark from private investors looking to take advantage of a new federal incentive to invest in low-income areas.

Oak Street fit the bill.

The Chicago-based company expressed interest in financing the entire cost of the stadium, but the Rays were concerned about the high interest rate the private equity firm expected to receive for its investment. Two other investment firms were interested in the opportunity, but Hagan said he was not sure if the Rays had been informed of that.

Christaldi confirmed Wednesday that Oak Street was interested in the so-called Opportunity Zone investment, which would have allowed the firm to delay paying capital gains taxes up to 10 years. If the deal had progressed, Christaldi would have been paid as the firm's attorney.

That lawyer-client arrangement is what raised questions about a conflict of interest that could have eroded public trust in the project.

A woman who answered the phone Wednesday at Oak Street said the firm wouldn't be commenting for this story, but Christaldi said Oak Street approached him after learning about the effort to build the Ybor City ballpark.

He said he didn't see any conflict with accepting legal fees if a deal came together.

"If there is anybody I can find to help fund a ballpark, I'm going to do that," Christaldi said. "Any deal would have been very public."

Christaldi said he wasn't privy to internal conversations among county officials about his involvement with Oak Street, but understood their position.

"I can respect that for sure, " he said.

The Rays declined comment Wednesday about Christaldi, but city and county officials said they knew the deal was in trouble weeks ago.

Rays president of baseball operations Matt Silverman came to Buckhorn's office at City Hall on Nov. 19 to tell the mayor "that they were going to pull the plug … for many of the same reasons that they highlighted yesterday," Buckhorn said.

Silverman said the team was planning to announce the decision on Nov. 27, Buckhorn said, but did not.

After that, "we continued to work on our side of the equation to construct a framework that would at least give us a point of negotiation," Buckhorn said, but "it's hard to negotiate with yourself."

"When we had no commitments from them that they were at least willing to put up half (the cost of the stadium), which was the starting point for us … there was no hope for a deal," he said.

That and the absence of a major Opportunity Zone investor doomed at least the current incarnation of the deal, the mayor said.

"The (Rays) could have been far more helpful getting this deal done than they appeared willing to do both in terms of a commitment that it's a 50/50 split and a more aggressive posture on the redevelopment of the areas around the stadium," Buckhorn said.

Hagan said he will meet with Buckhorn, Merrill, and Tampa Sports Authority President and CEO Eric Hart today to discuss next steps. He expects they will continue to flesh out details of the Ybor deal in the hope the Rays will resume negotiations.

Mark Conrad, a professor and director of the Sports Business Concentration at Fordham University, said Hillsborough may face some tough choices to resurrect the Ybor deal. While Tampa Bay may be one of the biggest media markets in the nation, the small crowds the team draws still makes it a questionable market for MLB. Other communities including Las Vegas and Portland, Ore., have expressed an interest in having a big league franchise, he said.

"(The Rays) didn't want too much of a financial commitment up front," Conrad said. "We have to see who has leverage and what the court of public opinion will be for greater public funding. Right now that's not an easy sell in a lot of the country."

But John Vrooman, a sports economist with Vanderbilt University, said MLB only rarely relocates a franchise, a tactic more common in the NFL.

"Almost all public/private stadium funding shares are the end result of a negotiation process that is often as aggressive and ultimately self-serving as a messy divorce," Vrooman said. "From the Rays perspective, they are probably seeking revenue certainty which is critical in the sports business, and they are frustrated with the gridlock in the give and take politics of local government."

Christaldi took issue Wednesday with the emerging narrative that the Ybor dream is dead. He said he's only been told that the goal of a first pitch at an Ybor stadium in 2023 is no longer viable.

"In all of the discussions I've had with folks, the finality was on Ybor in 2023," Christaldi said, declining to give specifics on who had told him that.

Referencing Rays president Brian Auld's comments that all options were once again viable in the Tampa Bay stadium quest, Christaldi said: "All options back on the table doesn't mean Ybor is dead or Hillsborough is dead. "

Buckhorn had a more pessimistic take on what happens if Sternberg holds true to his statement that he won't seek an extension of an agreement with St. Petersburg to negotiate with Hillsborough leaders when that memorandum of agreement expires Dec. 31.

"That would assume that we were in the rescue car heading for the hospital. And they're putting the paddles on the chest. And the rescue car has started, by the way," Buckhorn said.

Contact Charlie Frago @cfrago@tampabay.com or 727-893-8459. Follow@CharlieFrago