MIAMI (AP) Players from the Miami Marlins and Pittsburgh Pirates have expressed concerns about their two-game series next month in Puerto Rico because of the Zika virus.
Officials with Major League Baseball, the Marlins and Pirates expect the games to be played as scheduled May 30-31, they said Thursday. But the teams, MLB and the players' union are continuing discussions about the series, and union head Tony Clark described the health and safety concerns as serious.
''We recognize the importance of the trip,'' Marlins pitcher Craig Breslow said. ''But at the same time, our health and the health of our families is paramount.''
Major League Baseball Commissioner Rob Manfred said the league is in contact with the union about the issue.
The U.S. Centers for Disease Control and Prevention has said Zika can cause a birth defect called microcephaly, where infants are born with unusually small heads. The virus is most often spread by mosquito bites, but it also can be spread through sexual intercourse.
Since the virus lasts longer in semen than it does in blood, the CDC advises abstaining or using condoms if a man may have been infected while his partner is pregnant. It also can be difficult to determine whether someone has contracted Zika, because some infected people do not show any symptoms.
Breslow noted that CDC guidelines recommend that couples trying to get pregnant should wait six months if the man was diagnosed with Zika and was in an outbreak area.
''There are guys who are uncomfortable engaging in the lifestyle changes being recommended by the CDC,'' he said. ''I'm not sure that's fair to ask of 20- to 30-year-old men who are potentially looking to start families or expand families.''
Clark said the union is gathering as much information as possible from top scientific experts.
''As is the case with any international event, there are steps that have to be taken procedurally as we work towards a solution,'' Clark wrote in an email to The Associated Press.
MLB issued a statement expressing optimism the games in San Juan will be played as scheduled. Team officials, MLB, and the union share the same concerns regarding the issue, Marlins president David Samson said.
''We're all aligned on this to make sure that the safety of the players, the staff and the fans is always paramount,'' Samson said. ''I'm completely confident MLB and the MLBPA will work together with the CDC and any other required parties to ensure all of our safety.''
Samson and Brian Warecki, the Pirates' vice president of communications, said they expect the games to be played as scheduled.
''We are very confident that we are taking the overly cautious steps to ensure we have a very successful two game series in San Juan,'' Warecki said.
Pirates left-hander Tony Watson said the players would prefer not to go to Puerto Rico, ''but we don't have all the facts, either.
We're trying to walk a fine line here. It's an interesting situation that we're getting constant feedback from the CDC, doctors, experts, and it keeps blowing up bigger and bigger,'' he added. ''We're just trying to find the right thing to do for the players because health and safety is our No. 1 concern. It doesn't matter who it is, you bring one (case) back, or a couple months later something happens, it's just what we would not want to have happen at all.''
Manager Clint Hurdle said the organization has been transparent with the players and is talking through the situation.
''The one challenge now supposedly from people we're talking with is, the Zika virus is also in L.A., it's also in Miami, a smaller scale right now,'' Hurdle said. ''You're not going to play in Miami? You're not going to play in L.A., Puerto Rico? There's a lot of conversations that need to held. Our players have concerns in the room.''
The games are to celebrate Roberto Clemente Day, a league-wide tribute honoring the late Pirates Hall of Famer who was born and raised on the island. The matchup at Hiram Bithorn Stadium would be MLB's first games in Puerto Rico since the Marlins and Mets played in 2010.
U.S. health officials say Puerto Rico is the front lines of the nation's battle with Zika. There have been 550 confirmed cases in the island territory, including 71 pregnant women, according to the most recent data from the Department of Health.
There have been 91 cases in Florida, all travel-related, and no mosquito transmission of the virus in the continental United States.
AP Baseball Writer Ronald Blum, AP Medical Writer Mike Stobbe in New York and AP Sports Writers Will Graves in Pittsburgh and Bernie Wilson in San Diego contributed to this report.