But manager Eric Wedge said there is no reason to be alarmed.
"The trainer said he was good to go, but I just wanted to give him another day and make sure we don't have resolving issues as we make our way through the season," Wedge said.
Smoak, who is hitting .203, has been getting treatment and working to strengthen the hamstring each day. He said that he could have played on Tuesday but will instead aim to be back in the lineup on Wednesday.
"Everything's fine," Smoak said. "[I just need to] take of it now [so it doesn't affect me later]."