Ah, baseball. The A’s and Giants returned to the Bay Area on Thursday, and baseball was back at AT&T Park. The flags snapped in the crisp breeze. The fans streamed in, clutching their bobblehead giveaways.

Everything looked familiar.

Well, almost everything. Some things were missing. They always are as another season unfolds. Teams keep moving forward, shedding players and legends and turning that presence into their past.

The main thing missing at AT&T was Tim Lincecum. No Freak huddled in his black hoodie at the railing, watching intently. The flowing locks on the mound on Thursday night belonged to Jeff Samardzija, Lincecum’s hair apparent. His locker is now occupied by Sergio Romo.

For the first time since the start of the 2007 season — Lincecum was called up a month later — the Giants will open a season without No. 55.

That’s still hard for some people to handle. It was the single most-asked question I received about the Giants in the offseason: not about newcomers Samardzija or Johnny Cueto, not about Buster Posey. It was, “What’s happening with Tim Lincecum?”

And there’s still no answer.

In late January, Lincecum’s agent said that his two-time Cy Young Award-winning client was planning a showcase for teams in early February. That didn’t happen. And though he was reported to be throwing in a secret location in Arizona throughout spring training, he was like Bigfoot. No one had actually seen him.

“I just think he’s a perfectionist,” Giants general manager Bobby Evans said. “He wants to be completely ready.”

The Giants are as in the dark as everyone else. They wanted to attend a showcase to see the right-hander pitch — but they’ve heard nothing. According to one report during spring training, the Kansas City Royals found out where Lincecum was throwing, tried to get in to see him and were escorted out.

Lincecum’s invisibility raises questions about his rehabilitation. He had arthroscopic hip surgery Sept. 3, and at the time, his rehabilitation was pegged at five months. That would have put him in that February window.

But coming back from surgery is tricky, especially at 31 with a body that has endured a lot of wear and tear. Is his hip not responding? Is he only 80 percent? Is he finding that he now might be better suited to being a reliever, rather than a starter who is expected to pitch several innings?

No one knows because there has been no word from his camp for quite a while. Back in February, his father, Chris, was quoted as saying teams had made offers sight unseen, but that hasn’t happened.

Teams will set their rosters this weekend. Though that would seem to leave Lincecum out of a job, it could work to his advantage. He can see which teams really need starting pitchers, and if he has a good audition, could be signed to a guaranteed contract rather than a minor-league deal.

Who needs starting pitching? Well, the Dodgers are one team. Could the Giants’ most beloved pitcher end up in the uniform of their hated rival? The Padres also have been reported to be interested.

There’s a possibility Lincecum could end up in the Giants’ division, pitching against them. But right now, his status is a mystery.

A year ago, it was odd for Giants fans to see their team open without Pablo Sandoval at third base. Now they’re breathing a sigh of relief.

Sandoval, who is making $19 million a year in Boston, lost his starting job to someone named Travis Shaw, who is scheduled to make $550,000 this year. Sandoval, who had the worst year of his career last season, came into camp out of shape, struggled defensively and has become the butt of bitter jokes in Boston.

The Red Sox are reported to be at wits’ end with Sandoval and might be trying to replicate the lesson that Bruce Bochy and Brian Sabean taught Sandoval after the 2010 season. They benched him during the playoffs and gave him an ultimatum. “Operation Panda” had some success: Sandoval got fit and was instrumental in the Giants’ next two World Series runs. But he will turn 30 this season. It appears the Giants dodged a zeppelin when Sandoval turned down their offer in 2014.

I predicted that Sandoval would miss the comforts of San Francisco, where he was beloved and forgiven all his sins. That he would listen to “Sweet Caroline” at Fenway Park, and the phrase “Good times never seemed so good” would resonate with him.

Both Lincecum and Sandoval represented so many past good times for the Giants. But teams move forward.

Matt Duffy stepped forward last season and became a fixture at third base. The Giants’ rotation is set without Lincecum. Another season is about to unfold.

Ann Killion is a San Francisco Chronicle columnist. Email: akillion@sfchronicle.com Twitter: @annkillion