Mercer left Sunday night's game against the Dodgers at the end of the first inning with head and right ear discomfort.
Analysis: Mercer was injured when he slid into second base and got tangled with Dodgers second baseman Chase Utley while successfully breaking up an attempted double play on David Freese's ground ball to shortstop. Mercer singled to lead off the inning, extending his hitting streak to 11 games.
Goldschmidt had two hits and four RBIs for Arizona in Sunday's 9-7 loss to Colorado.
Analysis: Goldschmidt has reached base in 48 straight games against the Rockies, a mark that ties him with Mike Piazza, who did it from 1995-99. Goldschmidt has hit safely in 18 of 19 games overall, batting .408 with four homers, 18 RBIs, a .489 OBP and 1.160 OPS.
Gonzalez had a grand slam in the Rockies' 9-7 victory over the Diamondbacks on Sunday.
Analysis: Gonzalez has hit safely in 11 of 12 games, batting .408 with seven doubles. The Rockies host the Blue Jays on Monday, and Gonzalez will face Marco Estrada, against whom he is 1 for 5 with a homer and three strikeouts.
Reyes was hitless in three at-bats for Class-A Brooklyn on Sunday in his first minor league game since rejoining the New York Mets.
Analysis: Reyes, a star shortstop with the Mets from 2003-11, batted leadoff and was removed after playing six innings of errorless defense at third base. The 33-year-old Reyes signed a minor league contract with New York on Saturday.
Fernandez allowed one run in seven innings and struck out 13 in Sunday's 6-1 win over the Cubs.
Analysis: Fernandez improved his career record at Marlins Park to 24-1 with a 1.48 ERA. The right-hander has been pretty good everywhere else, too. This year he has a 2.28 ERA and 138 strikeouts in 94 2/3 innings. He is next slated to take the ball Saturday in Atlanta. In his lone start of the season against the Braves on June 21, he struck out seven over seven scoreless innings of one-hit ball.
The Pirates have promoted Kuhl from Triple-A Indianapolis, and the right-hander is slated to make his major league debut Sunday night against Clayton Kershaw and the Los Angeles Dodgers.
Analysis: The 23-year-old Kuhl went 6-2 with a 2.58 ERA in 14 starts at Indianapolis. He has compiled a 33-16 record with a 2.79 ERA in 81 starts over four minor league seasons since being drafted in the ninth round in 2013 from the University of Delaware.