"He was excellent," Balsley said of Kennedy, who got a no-decision.
In two starts with the Padres, Kennedy is 1-0 with a 2.63 ERA in 13 2/3 innings.
In addition to throwing his changeup for strikes -- Balsley said the pitch was a "plus-plus" pitch -- Kennedy did a good job working up in the strike zone, something that was missing when he was with the D-backs.
"I think everyone knows he has a good fastball," Balsley said. "But it's explosive. He throws 90 mph, but it plays like it's 93 or 94 mph. The high fastball is one of his strengths."
Kennedy was 3-8 with a 5.23 ERA in 21 starts this season with the D-backs. He is two seasons removed from winning 21 games and finishing fourth in the National League Cy Young Award vote.
The Padres see no reason why Kennedy can't return to that form -- and Balsley does not feel Kennedy is too far from it.
"It's not fixing things or changing them, but it's more getting them back to normal," Balsley said.
Balsley said Kennedy has been at his best when he has worked down and then worked his pitches up in the strike zone. Like with former Padres pitcher Chris Young, Kennedy's fastball up in the strike zone can appear a lot firmer than it actually is.
"I've watched a lot of video [from this season], and it had been more thigh-high this year," Balsley said.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.