SAN FRANCISCO -- Dave Roberts, his Dodgers in a historic tailspin, said this is the hardest stretch of his professional career. It didn't get easier before Monday night's game, as he defended in general an ever-changing lineup and in particular again starting outfielder Curtis Granderson , who is in a historic tailspin himself.

"You see what you've got when you go through a tough time like this," Roberts said.

As a one-time division lead of 21 games has withered to nine, Roberts has made liberal use of a 39-man active roster. He reiterated that he will soon settle on a set lineup with accommodations to a couple of positions where he will alternate depending on the opposing pitcher.

As for Granderson, who went 2-for-17 on the homestand, Roberts said he wants to "get Curtis right."

"Outside of the last couple weeks, he's had a great year, a very productive year," Roberts said of Granderson, who is hitting .209 on the season and .114 with the Dodgers.

But he also said Chris Taylor, who didn't start Monday, would return to the lineup Tuesday night and remain there the rest of the way, except for a scheduled day off. He added that he sees Taylor as his primary center fielder.

Roberts said Hyun-Jin Ryu was dropped from a six-man rotation in part because he wanted Clayton Kershaw and Yu Darvish to pitch on regular rest, as well as to protect Ryu after two seasons of injuries. Ryu will pitch a four- or five-inning simulated game Tuesday to stay sharp.

Monday night's lineup saw the return of first baseman Adrian Gonzalez , playing for the first time in six days after receiving another epidural injection for herniated disk pain. Gonzalez has yet to show his back can hold up to game demands. Roberts then moved Cody Bellinger to center field and Granderson to left, wanting a faster Bellinger to patrol AT&T Park's large center field.

Roberts said Chase Utley "has earned" increased playing time at second base, where a struggling John Forsythe has most of the starts. Austin Barnes could similarly take playing time from catcher Yasmani Grandal . And left field is a scramble, with Granderson and Joc Pederson now joined by Andre Ethier , looking to duplicate another late-season emergence after missing most of a second season if his back holds up.

"We have a lot of good players we're still evaluating," he said. "When you have the lead that we had, you can prioritize in health and trying to keep guys sharp versus trying to win every single game. But the challenge is keeping the sharpness and, obviously, we haven't been sharp. I expect us to turn it around with a core group. The positions we're talking about, anyone can debate who is that right person."

Roberts acknowledged his club's confidence "is probably wavering a little bit." He said he expected the last-place Giants "to bring their best" against the Dodgers.

"I'd like to think it's cause for us to dig a little deeper to beat these guys," he said.

Ken Gurnick has covered the Dodgers since 1989, and for MLB.com since 2001.