It's a prospect that has manager Don Mattingly excited about the future of his bullpen.
Guerra has been the Dodgers' de facto closer. Although Mattingly hasn't officially given him the title, he has called him his "ninth-inning guy" on several occasions. And Guerra has come through for Mattingly with six saves and a 2.18 ERA.
Jansen's season has been a bit more up-and-down -- he is 1-1 with a 4.13 ERA. But since returning from a shoulder injury in mid-June, Jansen has not allowed a run in 10 appearances (11 2/3 innings).
"Kenley is more of an explosive guy," Mattingly said when comparing the two pitchers. "It doesn't look like he's throwing that hard, but guys will swing and miss a lot. So you know his ball's got some jump to it."
As for Guerra: "Javy is more of a quick arm, good stuff, four-pitch mix," Mattingly said. "He's a tough pickup when you stand in there. That ball gets on you."
Closer Jonathan Broxton has been injured for most of the season and will be a free agent after the season. Both Guerra and Jansen could be long-term options in the closer role for the Dodgers, but Mattingly wouldn't speculate past this season.