After Yasiel Puig doubled to lead off the second, Walker was visited on the mound by D-backs manager Torey Lovullo and athletic trainer Ryan DiPanfilo in the middle of Joc Pederson's at-bat.
Walker's velocity went down during the first inning, which is what first caught Lovullo's attention.
"Sometimes the [radar] guns can be a little misleading," Lovullo said. "But it wasn't coming out of his hand as good and as crisp as I've seen it. That was enough for me to call the trainer out there. I know [DiPanfilo] had a long conversation with him and said there was a little bit of tightness there and was hoping it could loosen up."
Walker stayed in and allowed the Dodgers' only run of the game in the D-backs' 9-1 victory. Christian Walker pinch-hit for the starting pitcher with one out in the top of the third.
"It was my decision," Lovullo said. "He's just way too important of a guy and a piece of this puzzle for us to press on despite the circumstances in the early part of the game. That outweighed everything."
As of right now, no tests are scheduled, but that could change Sunday depending on how Walker feels.
Following the game, Walker said he was not concerned.
"I feel strong," Walker said. "Everything feels strong. I'm going to get some rest tonight and come in tomorrow and see how everything feels. I feel really good about it. I've felt a little tight before and it checked out to be nothing serious. It kind of feels like what I had before."