"I know I'm going to see a different doctor tomorrow -- just to make sure that things aren't that serious -- but it just hasn't progressed the way I was hoping it [would]," Tolleson told reporters on Saturday afternoon. "We've done the treatments for a couple of days -- and it's tough to really play short in the American League, much less the National League."
Kawasaki was optioned to the Minor Leagues on Monday. Players are not allowed to be recalled unless they have been down for at least 10 days, but exceptions are made when someone goes on the disabled list.
Tolleson had been hoping to avoid a stint on the DL, but his groin hasn't healed as quickly as initially anticipated. He sustained the injury after doubling against the White Sox on Tuesday.
"It just tightened up on me," Tolleson said. "There wasn't like a moment that made me stop running. I was able to coast into second, kind of shuffling off on each pitch was kind of painful.
"It felt much better [on Friday]. I tried to push the issue a little bit [on Saturday] and do some defensive work. Just controlled movements were OK, but reaction movements -- having to go different directions really fast -- it's still in there, it's still bothering me."
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, follow him on Twitter @gregorMLB and Facebook, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.