But for the next several seasons, at least, that rite of summer won’t be for him.

The man is booked.

“Tell me about it,’’ said O’Brien, who begins his fifth season calling Red Sox games on WEEI alongside mainstay Joe Castiglione tonight in Texas. “My time is pretty much absorbed.’’

That became more evident yesterday when WEEI and Entercom announced that O’Brien, who is also the play-by-play voice of ESPN’s “Wednesday Night Baseball,’’ agreed to a contract extension to remain in the Red Sox radio booth for the foreseeable future.

O’Brien confirmed that the deal begins next year and is for three years with a fourth-year option.

In terms of job security, it has been a fine month for O’Brien, whom WEEI accurately touts as “one of the most accomplished and versatile play-by-play broadcasters in the country.’’ On March 1, he came to terms on a four-year contract with ESPN, where he has also called NBA games, NCAA men’s and women’s basketball, and MLS, as well as the 2006 World Cup for ABC.

O’Brien, who is absent from 25-30 Sox broadcasts a season because of his ESPN duties, is appreciative of the flexibility his employers provide.

“It works perfectly because my bosses at ESPN and Entercom have allowed it to,’’ said O’Brien, a Quincy native who went to high school in New Hampshire and still resides there. “A lot of places wouldn’t necessarily stand for it, but it has worked, and I’m lucky it has because I’ve got two great gigs and I hope to do them both for a long time, and hopefully people will stand me that long.’’

O’Brien admits there are sacrifices that he must make. He laments that he doesn’t see his family as much as he would like this time of year. And he presumably spends more time on planes than most pilots.

Consider his itinerary over the next several days. Yesterday, he was in St. Louis to call the Cardinals’ opener against the Padres for ESPN. He was scheduled to fly to Texas for the Sox’ opener today. After the game, he heads to Indianapolis to call the women’s Final Four for ESPN. Following Tuesday’s championship game, he bolts for New York for “Wednesday Night Baseball,’’ then he’s off to Cleveland for the Sox game Thursday.

He might get exhausted if he didn’t enjoy it all so much.

“People won’t believe this, but I have that thought about how lucky I am every night I walk into Fenway,’’ said O’Brien, “almost as if somebody is going to come into the booth and ask me to go take my seat, as if this didn’t really happen. But it has, and I consider myself incredibly fortunate."