The visiting Athletics hope Cespedes can return Sunday and provide some support for Colon as they try to avoid a three-game sweep by the Los Angeles Angels.
Oakland (56-41) has totaled one run, 10 hits and 20 strikeouts in dropping the first two games of this series without Cespedes, who has been scratched because of a sore left wrist.
Manager Bob Melvin said the slugger hurt himself in the third round of batting practice Friday. Cespedes, who won Monday's Home Run Derby, has not gone deep in 19 games and could return Sunday.
"He feels better today, but until our training staff feels like he's 100 percent and not putting himself in a position where he could further injure it, it'll be day to day,'' said Melvin, whose club has totaled 13 runs over its last eight games.
Colon (12-3, 2.70 ERA), meanwhile, went 9-1 with a 1.59 ERA over his last 11 outings before the All-Star break. He has allowed three runs or fewer and pitched at least six innings every time in a 12-start span for the second-longest such run in Oakland history.
The 40-year-old right-hander, the oldest All-Star in club history, can tie Detroit's Max Scherzer and Tampa Bay's Matt Moore for the major league lead in victories. Colon has also posted a 1.75 ERA in winning his last five road starts.
Colon has not faced the Angels in 2013. He went 2-1 with a 1.66 ERA in three starts against them last year, with Albert Pujols going 4 for 10 off him.
Pujols, 4 for 8 in this series, is one of four Angels to homer in the first two games while the Athletics have failed to go deep.
Los Angeles starters have pitched 15 scoreless innings in this series. C.J. Wilson fell two outs shy of a shutout in Saturday's 2-0 win.
The A's captured the first five meetings with the Angels, who have taken the last three to move within a win of their first three-game home sweep of Oakland since Sept. 27-29, 2010.
The Angels (46-49) have won four straight at home as they send the struggling Jerome Williams (5-5, 4.60) to the mound.
Williams is 0-2 with a 19.13 ERA in three outings this month, failing to last past the fourth inning in any of them. He gave up six runs over 3 1-3 innings - his longest effort of this horrid stretch - in an 8-3 defeat at Seattle on July 12.
"I'm getting behind in the count and have to leave a pitch over the middle of the plate and get hit," Williams said. "I've got to control counts better."
The right-hander has allowed four runs - one earned - over nine innings in three 2013 relief appearances against the A's. He's 3-3 with a 3.86 ERA in seven career starts against them.