With Thursday being the deadline for WNBA players to opt out of the 2020 season, among a series of concerns from some players is that they did not receive detailed information until early Wednesday morning about the bubble they will be living in, sources told ESPN.

It meant they had a limited time to think through the information about the IMG Academy in Bradenton, Florida, and more specific details about the process of starting the season. One source said some players and teams might have a sense of feeling rushed to get ready to be in Florida by July 6, the targeted arrival date. Another source, though, said other players are not worried and are eager to get the process started.

Another concern among some WNBA teams is the amount of support personnel they will be able to bring, and there is some alarm about the rising number of coronavirus cases in Florida.

The 26-page document the players received Wednesday spelled out testing and safety procedures for before and after they arrive at IMG and provided details on lodging, meals and other aspects of their stay. The players were told the document is subject to change.

The document also included the league's commitment to support players' social justice initiatives.

The WNBA announced plans on June 15 to have a 22-game regular season -- with standard playoffs -- from late July to early October at the single-site facility at IMG. Players are to receive 100% of their salaries.

The NBA announced on June 4 its agreement on a single-site setting in Orlando, Florida, with players scheduled to arrive July 7 and start training camp two days later. In short, the NBA teams and players have had more time to digest the situation and make decisions than the WNBA players.

Another source, though, said WNBA teams and players understand that the league's officials have been working diligently to try to make complicated arrangements for an unprecedented type of season. WNBA commissioner Cathy Engelbert has reiterated that details are being worked out daily, with an eye on how the coronavirus pandemic and protocol around it may change.

Since the WNBA's announcement about its season, some players have opted out for safety concerns because of the pandemic, because they want to focus on social justice issues, or both.

More players might opt out. And some teams might push harder with regard to how many personnel they can have in the bubble, although the league appears to be standing firm on this.

Each team's travel party is allowed up to six basketball staff members -- including coaches and trainers -- along with two business staff members.

One franchise representative told ESPN that there was not enough support staff to adequately meet the players' needs and provide them the best chance to stay healthy and perform at peak level throughout the season.

A representative from another franchise said there is no "ideal" scenario and that teams and players will work together to solve whatever issues arise.

If WNBA teams take in full rosters of 12 players and a total of eight staff, that tally of 20 is considerably less than the 37 -- which can include up to 17 players -- that are being allowed for each NBA team in Orlando.

WNBA players are to receive physical and cardiac screening, fill out medical questionnaires and have three coronavirus tests before going to Florida. They have been instructed to self-quarantine a week before the arrival date of July 6. Players with a positive coronavirus test prior to travel won't be allowed to come to the site until after following extensive protocol from the Centers for Disease Control and Prevention.

Once at IMG, players -- along with all other personnel in the bubble -- will undergo another coronavirus test and then quarantine in their lodging area for four days. Testing for all personnel is expected to continue daily for at least the first two weeks everyone is in the bubble and periodically after that.

Face coverings will be required in the bubble except when players and all other personnel are in their lodging; eating meals; outside with proper social distancing; practicing; and playing games.

Training camps are to begin around July 10, with the season starting about two weeks after that.

One source indicated those committed to playing know there will be challenges to overcome, but they believe the season can take place safely. Others have varying concerns that might have increased since the June 15 announcement and now have to decide if they will play.