(CBS) After joining the White Sox following a trade with the Cardinals last July, outfielder Charlie Tilson’s big league debut turned into a nightmare.

In the fifth inning of his first MLB game last August, Tilson tore his left hamstring while tracking down a fly ball. Since that time, his focus has been on his rehab, which he said is going “great.” Tilson has been shuttling to and from Arizona at various times since December, and now he’s camped out there as White Sox spring training has opened.

“I’m out here, I’m participating every day,” Tilson said Tuesday. “I think the next step for me is to get to game speed. It’s a work in progress. I think I’m definitely close and getting better every day.”

The White Sox open spring training games late this month, and Tilson doesn’t yet know if he’ll be ready for them.

“That’s something you judge as the weeks go by,” he said. “I haven’t had a conversations with specifics like that up to this point, but all I can say is I’m feeling good and certainly ahead of where I anticipated.”

The plan had been for Tilson to be Chicago’s regular center fielder in the final two months of the 2016 season before the injury changed that. Now, Tilson is again trying to prove himself.

The 24-year-old Tilson, a Winnetka native, is a career .293 hitter in the minors and stole 46 bases in 134 games at Double-A in 2015.

“They know when I get to that competition mode, I’ll do whatever it takes,” Tilson said. “That’s why I need to be so confidence in my body before I put myself in that. It’s definitely tough to not necessarily be a full go.

“Speed is what got me here,” Tilson said. “It’s definitely my biggest asset, and being able to use that tool is very important to me. I’m very pleased with where I’m at.”

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