The southpaw Stults had a 2.20 ERA in five starts for the Knights. Dylan Axelrod started in Chris Sale's spot Sunday, with Sale being moved from the rotation to closer, but Axelrod was optioned to Charlotte after allowing two runs over 4 1/3 innings in a 3-1 loss to the Tigers.
A fifth starter won't truly be needed after Monday until May 15, when factoring in Thursday's off-day. That spot could go to Stults or 23-year-old Colombian native Jose Quintana, who will be called up from Double-A Birmingham on Monday, as reported by numerous media outlets Sunday.
Quintana, also a left-hander, has 26 strikeouts and 11 walks over 35 1/3 innings for Double-A Birmingham's rotation and last started on May 1.
"We'll see how it goes and make decisions based on how the next week shakes out," White Sox manager Robin Ventura said. "We're still going over stuff after we put Sale in the bullpen. I don't think anything is concrete."