Arteta said he did not know how long Hincapie would be out after picking up an injury during last week's goalless draw with Liverpool in the Premier League. Calafiori has been out since last month with a muscle injury and may take a few weeks to return, the Spaniard said.
"Willy and Leo... are doubts because they are not fit enough. Nothing serious," Arteta told reporters on Tuesday.
The absence of Hincapie and Saliba has left Arsenal with only four senior defenders for the Chelsea clash, including Gabriel Magalhaes, Myles Lewis-Skelly, Ben White and 16-year-old Marli Salmon.
However, Arteta said Arsenal will not be deterred from looking for redemption in the League Cup, after losing in last season's semis with 2-0 losses to Newcastle United in both legs.
"Football gives you another chance. We have been really consistent again in the competition and now we have to knock another big team out to be in the final. That's the mission," Arteta said.
"Hopefully, we learn from last year because it was painful, especially the manner in which the games went and the amount of chances we missed. Hopefully, this year we are better and more efficient."
Wednesday will be the first time Chelsea's newly-appointed manager Liam Rosenior takes on a fellow Premier League club, having beaten second-tier Charlton Athletic in his debut game at the weekend.
Former Arsenal player Arteta had played against Rosenior, then a Hull City player, in the FA Cup final of 2014.
"I've seen a few pictures of that. That's the beauty of football. Two very different careers but at the end facing each other tomorrow at Stamford Bridge in a semi-final," Arteta said.
"I know people that have worked with (Rosenior). They talk really highly of him so I wish him all the best apart from tomorrow."