Field was stunned to join the Rockies and said he had "no idea" he would start.
Shortstop Troy Tulowitzki was out with a sore left hip after playing Saturday, soreness that had kept him from playing Friday. Manager Jim Tracy wanted to rest Tulowitzki because he would have two days off with the Rockies not playing Monday. Tracy said Tulowitzki would be ready to play Tuesday at Milwaukee, where Tracy wants to use his most competitive lineup since the Brewers are trying to hold off the Cardinals in the National League Central.
Infielder Chris Nelson, who played shortstop in the Majors for the first time on Friday, came into the clubhouse Sunday with a protective boot on his left heel. Heel soreness bothered Nelson at the end of the Triple-A Colorado Springs season and delayed his activation to the Rockies until Friday, three days after he was brought up.
Also, second baseman Mark Ellis was hit in the back of the helmet and neck with a pitch on Saturday thrown by Reds reliever Carlos Fisher. Ellis had neck soreness Sunday, but no concussion symptoms or headache. As a precaution, Tracy didn't want to start Ellis but said he might be available to play defense.
Field, 24, who was in big league Spring Training this year with the Rockies, hit .271 at Tulsa with 17 home runs and 61 RBIs. He primarily played second base this year, but has extensive experience at shortstop.
Field said he was in Oklahoma on Saturday attending a reunion of his wife's family, and was driving back to their home in Waco, Texas, when a member of the Rockies Minor League department called and said Field might be going to the big leagues.
"We all kind of held our breaths ... finally got the call around midnight," Field said. "They booked, I guess, the first flight they could find out of Dallas. It was at 7 this morning. We ended up leaving Waco, which is about two hours away, at 3:45 to get there.
"It's pretty surreal, and I'm really excited to be here."