The Celtics season ended less than a week ago, and the rumor mill has been buzzing with talks of free agency, retirement, and who will be on the sidelines next fall. With all the questions surrounding the Celtics this summer, here are five storylines to watch for as the offseason unfolds.

1. The possible return — or departure — of Doc Rivers: Speculation of Rivers’ departure from Boston was prevalent throughout the entire postseason as talks of the coach stepping down to spend more time with his family heated up.

The possibility of “lasts” was mentioned in every round: Last game at TD Garden? Last playoff series? Last game as coach of the Celtics? Rivers has given thought to the looming question, but it is too soon for him to commit to a decision.

“I am not going to say which way I am leaning — and I am one way — but I could look you in the eye and say that I have not made a decision,” he told WEEI’s Dennis & Callahan on Monday. “We have only had a small conversation, and we are going to do that in the next week or so.”

He will take his personal and professional life into account and weigh returning home to be with his wife and four children or returning to the sidelines to be with his coaching staff and 15 players?

“The only reason you stay is the love for the guys you coach and the organization, Danny [Ainge] and the guys you work for, knowing that if you do leave that you’re not going to ever get that back,” Rivers said.

“You can get a coaching job back and there’s no doubt about that, but I don’t think I will ever get the situation that I have here in Boston back, so that will be difficult to leave. The other side is so strong as well with the family, and it is going to be an interesting decision and I don’t know what it is yet.”

2. Paul Pierce and the player option: There’s no question where Pierce wants to end his career — as a Celtic. What is unclear is, though, is the captain’s next move. He has a player option on his contract, which must be exercised by the end of the month.

Early reports from the Boston Herald noted the Celtics are working quickly to talk with Pierce, having already scheduled a meeting with Pierce’s representatives following the draft.

Pierce is set to make $21.5 million in the final year of his contract. He has spent his entire career in green and wants to help the C’s stay competitive. At the start of the 2010 season, he said that he wants to do what is best for the team. Now it is a matter of what is best for both Pierce and the Celtics.

3. Ray Allen’s future in Boston: While the majority of the Celtics roster is up for free agency this summer, Allen is the only member of the starting lineup on the market. Among Allen, Pierce, and Kevin Garnett, he is the first with an expiring contract, posing the question, “Is this the end of the Big Three?“

Allen has said he would like to return to the Celtics. There are teams with money to spend, though, and the Celtics have to address several contracts. The length of Allen’s contract demand could pose a challenge.

And then there is the dollar value. According to the Boston Herald, one league official recently placed Allen’s value on the wildly competitive free agent market at approximately mid-level exception range, or about $5.6 million.

Guesstimating the value of Allen’s next contract is tricky. The combination of his age and sharpshooting could sway team’s to different ends of the contract scale. On one hand, Allen turns 35 in July and struggled offensively after Game 2 of the NBA finals. On the other hand, Allen is one of the best-conditioned players in the league and set a finals record with 3-point performance.

“I believe I’m so far ahead of the game that I’m able to play longer,” Allen told WEEI.com during the regular season. “People look at basic standards of guys my age at 34, like some guys at 34, there’s no way they could play basketball right now. And I’m thinking at my age now, I can go even a few more years doing what I’m doing the way I’m doing it because for me, it’s not rocket science.”

4. 2010 NBA draft: Talk about switching gears. Just one week separated Game 7 of the NBA finals and the 19th pick in the 2010 NBA Draft. Unlike the case on some other teams, there is not one glaring hole the Celtics can easily shore up on Thursday. Since they face so many uncertainties in the free agent market this summer, it is impossible to determine exactly how a draft pick will fit in next season.

There is talk of drafting a shooting guard, to either take the place of or back up Ray Allen, depending on his free agency. NBADraft.net projected Oklahoma State’s James Anderson as a possible option at the 2 spot.

Between the injury to Kendrick Perkins, the possible retirement of Rasheed Wallace and the expiring contract of Shelden Williams, the Celtics also have to get bigger this summer. According to Draft Express, one candidate is Florida State center Solomon Alabi.

The Celtics also have the 52nd pick on Thursday night. Danny Ainge has proved in the past that whether it is a mid-first-round selection or a late-second-round choice, the C’s have an eye for talent at any point in the draft.

5. Rebuilding the bench: They can’t be counted on one hand, and barely fit on two. This summer nearly the entire Celtics bench is up for free agency — Tony Allen, Nate Robinson, Marquis Daniels, Brian Scalabrine, Shelden Williams and Michael Finley face new contracts for next season.

Of the group, Allen and Robinson seem to have the highest likelihood of donning green next fall. They made their marks during the playoffs and their energy was critical off the bench. Allen, one of the Celtics toughest defenders in the postseason, has already declared he would like to re-sign in Boston. “I am a Celtic,” he told WEEI.com. “I love being a Celtic. It’d mean everything in the world [return next season].” Robinson has also stated he “feels wanted” and would like to play in Boston next season.

But at what price? The Celtics have numerous spots to fill on the bench and Allen and Robinson could garner higher offers from other organizations.

As the Celtics address their current players, they will have to search around the league for new team members. Age is an issue, as it caught up with them late in Game 7. The Celtics still have a strong core, now they need surround it with reliable reserves who are committed to the system.

One more thing …

LeBron’s Big Decision: Last summer the Celtics built their team to beat the best in the East. The plan paid off when they eliminated the 2009 conference champion Orlando Magic from the playoffs.

But it’s a little different this summer. LeBron James is on the market and whichever team he signs with will become an instant contender. (Especially if he joins another star free agent, such as Dwyane Wade or Chris Bosh.) So as the Celtics — and organizations around the league — address their own teams, James’ decision could impact the decisions of those who could have to face him on their path to a championship.