Yoshinobu Yamamoto said Sunday he is confident about returning from a shoulder injury before the end of the season.

“Of course,” he told Japanese reporters, with a chuckle.

However, neither the Dodgers nor their star Japanese right-hander has yet set a target date for Yamamoto’s return, leaving his status unclear as MLB’s July 30 trade deadline approaches.

“I just want to recover as quickly as possible,” Yamamoto said in Japanese, “and direct my rehabilitation in a way to make that happen.”

While Yamamoto hasn’t pitched since June 15 because of a strained rotator cuff, he said he is now pain-free and has been extending the distance of his flat-ground long toss sessions.

According to manager Dave Roberts, Yamamoto has gotten to about 200 feet in catch play, a sign that bullpen sessions could be on the horizon for the 25-year-old starter, who signed a record-breaking $325-million contract with the Dodgers this offseason.

“I’m at the stage where I’m gradually increasing distance and effort,” Yamamoto said. “I feel it’s going extremely well.”

Yet there is still no firm date on when Yamamoto might get back on a mound, or begin a minor-league rehab assignment, or eventually return to a Dodgers rotation that will desperately need him come the playoffs.

“If he were to come back,” manager Dave Roberts said, “he would certainly be an impact guy.”

For now, though, that ominous “if” remains — leaving the Dodgers in a somewhat awkward position going into next week’s trade deadline.

If the team knew Yamamoto would be back pitching like he did before his injury, when he was 6-2 with a rotation-best 2.92 ERA, it would lessen their need to try to add another front-line pitcher before the deadline — a tall task in a seller’s market with few ace-caliber arms available.

Dodgers pitcher Yoshinobu Yamamoto delivers against the St. Louis Cardinals on March 30.

(Wally Skalij / Los Angeles Times)

On the flip side, if the Dodgers knew Yamamoto was out for the rest of the year, it might make the front office more comfortable parting with top prospects to acquire a talented arm such as Garrett Crochet of the Chicago White Sox or, in the unlikely event he becomes available, Tarik Skubal of the Detroit Tigers.

Instead, the team finds itself in a “tricky” situation, as Roberts put it, with Yamamoto representing one of several key players (along with Max Muncy, Walker Buehler and others) whose ability to contribute come the postseason is unknown.

That dynamic is unlikely to change before the deadline next Tuesday.

“I don’t think we’ll learn a whole lot over the next 10 days, I don’t,” Roberts said of Yamamoto’s recovery.

Yamamoto said he believes the club’s training staff has a rough idea of his recovery schedule, but he didn’t offer any specifics while meeting with reporters on Sunday.

He said his recovery hasn’t been slower than he anticipated, but he acknowledged some frustration at having his productive rookie season sidelined after just 14 starts.

“It’s very upsetting to not be able to pitch in a game,” he said. “I think that by carrying those feelings into my rehabilitation, it will lead to me returning as early as possible.”

The Dodgers also remain hopeful of that — for Yamamoto to make a full recovery, rediscover his early-season form, and be a key member of their rotation in time for the playoffs.

The longer he remains out, however, the dimmer those chances become.

Jason Heyward returns

Outfielder Jason Heyward was activated from the injured list prior to Sunday’s game after missing two weeks with a knee contusion. Fellow left-handed-hitting outfielder James Outman was optioned to the minors in a corresponding move.

Heyward is batting just .203 and was in a deep slump before going on the IL earlier this month — his second time being sidelined by an injury this season.

Outman, who opened the season as the Dodgers’ center fielder before being optioned in mid-May amid early season struggles, failed to offer much more production, going just three-for-15 in Heyward’s absence.

Short hops

Injured relievers Brusdar Graterol (shoulder) and Michael Grove (lat tightness) were scheduled to begin minor-league rehab assignments with triple-A Oklahoma City on Sunday. Roberts said both could require five-to-seven outings before returning to the big leagues. Ryan Brasier (calf) is also nearing a rehab assignment, Roberts said.