Triston Casas is working his way back to the Red Sox. It won’t be this week, but it will be soon. The 20-day limit on his injury rehab assignment means he would have to return Aug. 19.

The first baseman has played eight games with the Triple-A Worcester Red Sox as he returns from the rib cartilage injury he suffered on April 20. He’s hit the ball well, with five doubles, yet he’s not quite ready to return.

“He feels he still needs more,” Red Sox Manager Alex Cora said Sunday. “We’ll keep getting him at-bats. He feels close to 100 percent in a sense. One hundred percent for him is kind of like how he bounces back the next day. How he bounces back from batting practice and all that stuff.

“He’s still going to be down there. Most likely next week he’ll stay there and then we’ll see what happens.”

The Red Sox have the luxury of being patient with Casas thanks to Dominic Smith. From June 29 through Sunday’s loss to the Astros, Smith is hitting .267 with 12 doubles and three homers. He has also been a steady defender at first base.

Smith, a first-round pick of the Mets in 2013, has gone back to the fluid swing that made him one of the best hitting prospects in his draft class. He has worked with hitting coach Pete Fatse to rediscover that form.

“He has a very good hit tool,” said Fatse. “He’s got a lot of power…. He’s done a terrific job. Just trying to get him back to understanding who he is and what made him the coveted player he is.”

The only problem with Smith is he is a left-handed hitter. So is Casas. They would fit nicely as a complimentary pair if one hit right-handed. Instead, it’s going to be difficult to keep both on the roster when Casas returns.

If Sox fans are worried about that, they can rest easy knowing that Smith is not.

“This is something that, you know, takes time to learn,” Smith said on the “310 to Left” podcast last week. “You’re not just going to learn that when you’re 18 years old, fresh at the major league complex, starting your professional career.

“I think over the years you just learn how the business works. You understand certain things and the stuff that you can’t control. If you sit there and worry about that stuff it’s going to drive you crazy. It’s going to take away from your performance. You’re not going to be able to sleep some nights. So I think, for me, I just love every day.”

It’s a refreshing attitude from a refreshing player. Smith has become an important part of the clubhouse, a veteran who is coming into his own voice in his eighth major league season.

It would be hard to imagine the Red Sox letting him walk away after the season he has had. The good news for Smith is that, if they do, he will have plenty of other teams lining up to add him to their roster. That’s a massive development for a player who has been released by two teams this season (he exercised an opt-out in his contract each time.) He has rebuilt his resume and helped this team rebuild its connection with the fans.

He’s also helped them get back into the playoff race. And after a weekend where the Sox scored only 10 runs while being swept by the Astros, the Sox will clearly need as much help as possible if they hope to nail down a playoff spot at the end of the season.

Tom Caron is a studio host for the Red Sox broadcast on NESN.