SAN DIEGO -- Yu Darvish is back with the Padres -- a potentially major boost for a strong-but-thin San Diego rotation ahead of the stretch run.

Darvish, who was placed on the restricted list in early July while he tended to a personal family matter, was reinstated on Friday. Upon his return, he was placed on the injured list, as he builds his way back from several months away from the mound.

The Padres anticipate that if all goes well, the 38-year-old Darvish will pitch for them again this season.

"It was a difficult decision to leave, obviously," Darvish said through interpreter Shingo Horie. "Things can get complicated sometimes. But, again, it's really good to be back. ... All in all, it's a great day."

Through a team spokesperson, Darvish declined to answer questions about the nature of his temporary departure from the club.

"I'm just full of gratitude," Darvish said. "It's really nice to be back."

He got straight to work, too. Darvish threw a 27-pitch bullpen session ahead of Friday's game against the Mets. While away from the team, he'd been throwing as well, though he hasn't built up beyond one up-and-down (essentially two simulated innings).

That means Darvish is likely still weeks away from rejoining the big league club. But he indicated that his placement on the IL was entirely "a matter of ramping up" and unrelated to the injuries he dealt with earlier in the season (including inflammation in his right elbow).

"The bullpen was very good today," Darvish said. "I'm very satisfied with how things went out there. As far as moving forward from here, I'll have some conversations with the appropriate people."

In 11 starts this season, Darvish posted a 3.20 ERA with 53 strikeouts and 15 walks in 56 1/3 innings. He missed time early in the year with a neck issue, then landed on the IL in June with a groin strain. As he approached his return from that, Darvish was sidelined by elbow inflammation.

Shortly thereafter, Darvish went on the restricted list -- meaning he was still under club control even though he was no longer with the club or technically a part of its roster.

Now he’s back -- as is right-hander Joe Musgrove, who made his third start in his return from right elbow inflammation on Friday night. That gives the Padres a theoretical postseason rotation of Dylan Cease, Joe Musgrove and Darvish, with Michael King as the swing-man and Martín Pérez as the fifth option.

“When [Darvish] is ready to come back, he’s going to be in the rotation,” manager Mike Shildt said. “So it’ll have an impact -- and a positive impact.”

On Thursday, the club optioned rookie knuckleballer Matt Waldron to Triple-A El Paso, which raised questions about the short-term state of the rotation. (The Padres still haven't named a starter for Monday in St. Louis, though Randy Vásquez is the obvious candidate for a callup.)

Darvish's return does little to address those short-term question marks. But he sure adds a measure of stability -- particularly considering that as recently as two days ago, the club wasn't sure whether Darvish would return.

Darvish said he contacted Padres general manager A.J. Preller on Wednesday about the possibility of returning. The two formalized those plans on Thursday.

"A.J. has been more of a friend to me during this time," Darvish said. "He's been very supportive and very understanding and compassionate over these two months, and I really do appreciate it."

Darvish joked that the Padres' recent surge in the standings made him question whether his teammates would want him back. Unsurprisingly, however, his return was greeted warmly in the Padres clubhouse, where Darvish is among the most beloved and respected players.

"From my standpoint, you've been away for such a long time, and you feel a little bit nervous," Darvish said. "But all the smiles and all the hugs, that kind of eliminated all that feeling. It was great."