Through his first 14 appearances with the Padres this season, he allowed just 18 walks. In his last two starts, Banks has allowed an uncharacteristic 13 walks in just 8 1/3 innings on his way to two consecutive losses.
On Tuesday night at Chase Field, Banks (3-6) allowed seven walks, including four in the first inning -- three of which came around to score -- as the Padres fell to the D-backs, 7-6.
Banks had never allowed more than three walks in a game at the Major League level before his last start against the Brewers.
"I haven't been able to locate [my fastball]," Banks said. "The last two games just seem really out of whack and just really strange.
"I'm not the most dominating pitcher but, usually I can keep us in the game. I just haven't done that the last two starts."
The seven walks are the most by a Padres pitcher since Clay Hensley walked seven on June 5, 2006. Banks threw 87 pitches -- 45 strikes, 42 balls.
Banks allowed four first-inning runs, then two more in the fourth on Adam Dunn's first homer with the D-backs, a 396-foot shot to right field.
Padres manager Bud Black and pitching coach Darren Balsley were looking for any changes in Banks' mechanics but couldn't find anything that would suggest such a stark contrast in accuracy.
"It just seems the fastball command has eluded him the last couple starts," Black said. "The secondary pitches have been a bit erratic too. I couldn't tell if there was anything mechanic-wise. Whether he's trying to be too fine, I'm not sure, but that's something that we have to talk about."
The Padres nearly erased Banks' poor outing in the ninth inning with a rally that came up just short. D-backs closer Brandon Lyon started the inning in a non-save situation.
Lyon allowed a leadoff double to Edgar Gonzalez. After Scott Hairston struck out, Brian Giles walked. Kevin Kouzmanoff singled to load the bases, putting the tying runner at the plate in the form of Adrian Gonzalez.
Gonzalez singled on a line drive to center fielder Chris Young, who botched the play, as two runs scored. With only one out in the inning, No. 5 hitter Chase Headley followed with an RBI single, putting the tying run at third base.
That was when D-backs manager Bob Melvin had seen enough and put in setup man Tony Pena to close the door. On the first pitch, Padres catcher Nick Hundley hit a bouncer back to Pena. With Gonzalez sneaking off third base, Pena was able to get him in a pickle and retire him, but in the process, Hundley and Headley advanced two bases. But it was all for naught when Luis Rodriguez flied out to center to end the game.
"We've been consistent about going all the way until in the end; it's just we've come up short," Adrian Gonzalez said. "We're not just going to give away at-bats. We did a good job there and got them into a little bit of trouble, but they were able to stay on top."
Gonzalez tied his career-high with four hits in the game, the 10th time in his career he has reached that total.
The Padres trailed, 4-0, going into the second inning and loaded the bases with none out. The first two batters -- Adrian Gonzalez and Headley -- scored after both singled. Rookie shortstop Sean Kazmar hit a sacrifice fly for the first RBI of his career, scoring Headley.
Dunn's two-run homer put the D-backs up, 6-2, in the fourth, and it stayed that way until the eighth, when the Padres tacked on another run on a Jody Gerut pinch-hit RBI single.
"Every hit in the ninth was big; we just couldn't get that real big one at the end," Black said. "I thought all our guys had good at-bats in the ninth."