CHICAGO -- The three-month intermission between Spring Training and Summer Camp afforded Kyle Hendricks some extra time to continue working on a long-term project. The Cubs starter used that period to keep honing his breaking ball.

"My curveball, I've been working on a ton," Hendricks said in a recent Zoom chat with reporters. "I worked on it even more during this quarantine. It gave me a lot of time to do that, to kind of mess around a little bit with pressure, just how to spin it, learning how to spin it better.

"Right now, it's the best my curveball's felt."

During Sunday night's 7-3 exhibition loss to the White Sox, Hendricks was able to take his curveball out for a spin against batters not wearing a Cubs uniform. And in the second inning, the Cubs' Opening Day starter showed off a curve that flashed elite potential, following years of ups and downs with the pitch.

Hendricks started White Sox rookie Luis Robert off with a curve that broke low and away, enticing a swing that finished with the outfielder losing his grip on the bat and sending it helicoptering into foul territory. Two pitches later, Hendricks froze Robert with another curve that hit the low-and-away corner for a called third strike.

"Great spin on that breaking ball," Cubs manager David Ross said. "He's able to throw it 0-0, he's able to throw it for chase. I think that's the key for him, is being able to manipulate that where he wants to throw it."

That strikeout pitch to Robert featured a spin rate of 2,964 rpm, per Statcast. Last season, Hendricks reached that level only five times out of 279 curves overall, topping out at 3,069 rpm on a strikeout to Tony Wolters on June 4. He averaged 71.5 mph and 2,789 rpm on his curve in 2019. On Sunday night, the averages were 72.2 mph and 2,794 rpm on the dozen he threw.

Hendricks is predominantly a sinker (42.4 percent of his pitches in 2019) and changeup (27.8 percent) pitcher, mixing in the four-seamer and curve as well. Last year, he used the breaking ball 9.5 percent of the time. If it can be a more effective weapon, maybe Sunday night's 14 percent usage is a sign of things to come this year.

Against the White Sox, Hendricks threw the curveball four times as a first pitch, four times in an 0-2 count, twice in a 1-1 count and once apiece as an 0-1 and 1-2 pitch. That will give the Brewers something to think about as they prepare to face Hendricks in Friday's season opener at Wrigley Field.

"It's just so difficult being a two-pitch pitcher in this game today," Hendricks said. "So using that curveball not just in an early count, but learning how to get guys out with it, learning how to use it in middle counts, moving it around the strike zone -- I’ve been doing a lot of things with my curveball. I think it's going to open up a lot in my game."

Carraway on his way?
The Cubs have not officially announced the move, but the team is planning on adding lefty reliever Burl Carraway to its pool of players working out at the alternate training site in South Bend, Ind. Chicago picked up the 21-year-old in the second round of the 2020 MLB Draft last month.

"He could end up being a fast mover," Cubs vice president of scouting Dan Kantrovitz said after the Draft. "And that's something that you don't really want to say about somebody unless they are actually going to be one. He's got an upper-90s, explosive fastball that's comparable to some of the better big league fastballs today.

"And he's got two different types of breakers that are true knee-bucklers. We feel like he's an impact arm."

Carraway averaged 15.6 strikeouts per nine innings in his time at Dallas Baptist, punching out 17 in 9 1/3 innings before the '20 season ended and 72 in 41 2/3 innings last year. He will have to go through the COVID-19 intake screening before potentially being added to the 60-man player pool by the Cubs.

Worth noting
• Ross noted that Anthony Rizzo (back tightness) was doing well on Monday, following a full workout on Sunday. Rizzo was slated to do some light hitting Monday before facing live pitching in Tuesday's workout at Wrigley Field. If that goes well, Rizzo might be cleared to play in Wednesday's exhibition game against the Twins.

"He continues to move in the right direction," Ross said. "Good positive feedback."

• José Quintana, who is recovering from surgery to repair a lacerated sensory nerve in his left thumb, has built up to flat-ground catch from a distance of 90 feet, per Cubs pitching coach Tommy Hottovy. Barring any setbacks, Quintana could be cleared for a bullpen session within the next 7-10 days.

"When we can get him back, we're going to be excited," Hottovy said. "But, we obviously understand the road he has to take to get back to that point."

• Right-hander Tyler Chatwood is scheduled to throw a simulated game Tuesday at Wrigley Field. The goal will be for Chatwood to throw around 80 pitches in that environment as his final tune-up for Sunday's start against the Brewers.

"I'm excited to see what he can do once the season starts," Hottovy said, "because he's hungry. He's in a really good place mentally and physically, and he's ready to kind of hit the ground running.

Up next
Following a light workout on Tuesday, the Cubs resume their exhibition slate Wednesday with a 6:05 p.m. CT tilt against the Twins at Wrigley Field. Lefty Jon Lester will start for Chicago, with righty Alec Mills working behind him. Watch the game live on MLB.TV and MLB Network.