Dodgers’ Kenley Jansen shines after returning from DL

When Kenley Jansen went on the disabled list in late May, the reliever also drew a reprimand from Dodgers Manager Don Mattingly.

On Friday, though, Mattingly was singing Jansen’s praises because the right-handed pitcher has sparkled since returning from the DL on June 18.

“He’s been doing the job,” Mattingly said. “His ball’s got some jump to it … and his slider is getting better, and he’s willing to use it more, which makes him a lot tougher at-bat.”

Before Friday’s game against the Washington Nationals, Jansen had held opposing batters to a .079 average (three for 38) and was averaging 14.33 strikeouts per nine innings. He also had an 112/3 -innings scoreless streak.

“I’m making better adjustments [against batters] now than I was last year,” Jansen said. “Last year when I’d get into trouble out there, all I’d do is keep throwing my fastballs. Now I have some pitches to work on, and I’ve learned how to slow the game down better.”

Jansen, a 23-year-old native of Curacao, was put on the DL because of inflammation in his throwing shoulder. But he hadn’t immediately told the Dodgers he was hurting, which annoyed Mattingly.

The 6-foot-5 pitcher said he learned his lesson.

“All this stuff is new for me,” Jansen said. “I just tried to stay out there and keep competing. But then a little injury becomes big.

“Now I know when something bothers me just let them know right away,” he said. “I really don’t want to be on the disabled list; it’s not fun at all.”

Mattingly said: “We’re using [Jansen] in a lot of different spots. Sometimes we’ll use him when we think we can get two innings out of him. Other times we’ll use him a little bit later in a one-inning situation.”

“He’s doing a lot better job of holding runners,” Mattingly added. “He’s been really good about changing his tempo.”

Jansen said he is less concerned about his recent statistics than about his health. “The important thing is my arm feels better; it’s not bothering me,” he said.

A return to the Ravine

The last time the Nationals’ Davey Johnson managed at Dodger Stadium was 11 years ago when he was managing the Dodgers.

Johnson, 68, was chosen last month to replace Jim Riggleman, who abruptly resigned. Before Friday’s game, the Nationals were 8-12 since Johnson took over.

The Nationals job is Johnson’s fifth stint as a manager, and his first since managing the Dodgers in 1999 and 2000. The Dodgers were 163-161 in his two years, and Johnson was fired after the 2000 season.

“I thought I was making progress, but it didn’t last long enough to make a difference,” Johnson recalled of his Dodgers tenure. Even so, “it’s always nice to come here,” he said. “You can’t beat the weather; love the ballpark.”

james.peltz@latimes.com