Mercer has only one extra-base hit (a double) among the total of 11 that depress his average to .183, with an OPS of .442.
In manager Clint Hurdle's view, the 27-year-old just needs to remember that it is a long season.
"He hasn't gotten out clean, and we have a tendency to try to make up for lost time," Hurdle said, "to try to get five hits in three at-bats.
"His No. 1 is, he's got to get started early [with the batter's box approach]. That's getting ready to hit, the preparation -- his first move to the ball, his trigger. It needs to be earlier."
There is also the obvious added pressure that comes with expectation. Last season, as a frequent contributor but, still, only Barmes' lieutenant, Mercer batted .285 with 32 extra-base hits (22 doubles, two triples, eight homers) giving him a .772 OPS.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. This story was not subject to the approval of Major League Baseball or its clubs.