"I felt like Gonzalez was the top priority to make sure he doesn't get overused and gets some rest," he said. "It was matchups from there."
Mattingly further explained that by moving Justin Turner to first base, the decision on third base came down to Alberto Callaspo or Alex Guerrero, with Callaspo getting the nod because of the matchup with Rangers starting pitcher Yovani Gallardo.
"If Alex had been the better matchup, we'd play him at third," said Mattingly.
Neither Callaspo nor Guerrero has faced Gallardo, but the switch-hitting Callaspo can bat left-handed against the right-handed Gallardo and Callaspo is considered a better defensive third baseman than Guerrero.
Mattingly said he believes the current Dodgers roster is "better equipped" to adjust to designated hitter rules than in previous seasons.
"A couple of years ago, we weren't very good in Interleague games," he said. "Now we are a little different club."
He said he likes the scheduling of four consecutive games against the same team, even though they are in different time zones, because "it makes it easier to get ready for them."
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.