CHICAGO -- The Cubs were still evaluating the extent of starter Cade Horton's back injury Thursday, leaving the National League Rookie of the Year candidate's status for the wild-card playoff series in question.
Manager Craig Counsell said, "Cade is on track still," though an MRI on Wednesday showed "some areas of concern" in the ribs.
"Right now, Cade is a go," Counsell said, adding that Horton is "adamant he can pitch."
Counsell said another physician will look at the imaging. Horton is scheduled to resume throwing on Friday after being off the past two days.
"We want to make sure we use this time to let Cade tell us how he feels, let Cade show us how he feels, consult our doctors and let them make recommendations and get the best decision we can make," Counsell said.
Chicago will play the San Diego Padres in Game 1 of the National League Wild Card Series on Tuesday. The Cubs' magic number for clinching the top wild-card spot -- and home-field advantage in the first round -- was at two over Padres entering Thursday's game against the playoff-contending New York Mets.
Horton is 11-4 in 22 starts and 23 appearances. The 24-year-old right-hander has a 2.67 ERA that ranks second among qualified rookies.
Horton left Tuesday's start against New York after three innings because of back tightness. He was sick following his previous start and had been coughing, which led to the issues in the back and ribs.
Counsell said the Cubs won't announce their postseason rotation until next week.
"We're at this phase where we're starting to put plans into place," Counsell said. "We have multiple ones. We've got four baseball games left, which affects things."