He can feel the difference in his arm, he said. Now comes the matter of translating that difference into his pitching.
Nathan said he has spent his early bullpen sessions focusing more on commanding his pitches on both sides of the plate. It's not necessarily a big difference for him, but it's an earlier priority.
While much was made of Nathan's velocity last season at age 39, including a fastball that averaged 91.6 mph, Nathan also had a drop in the percentage of fastballs in the strike zone, falling from 50.5 percent in 2013 to 48.9 percent last year. Part of that likely resulted from a drop in swings and misses, but Nathan also struggled to spot the fastball on the corners as opposed to the plate.
Though Nathan's runs, batting average and BABIP allowed dropped down the stretch last year, his walk rate did not. He walked more batters after the All-Star break (15) than before (14), but three of the second-half walks were intentional.
Manager Brad Ausmus said Nathan's pitches looked crisp so far in early sessions, settling into the arm slot he found late last year.
Sunday was Nathan's second bullpen session this Spring Training. He'll have at least three more before games begin March 2. Ausmus said the process of gearing up Nathan this spring will be similar to last year, pointing out that Nathan had to prove he was ready.
"I don't think Joe will be handled any differently in Spring Training," Ausmus said. "We've got to make sure he's at full strength once the season starts. He looked good the other day."
Jason Beck is a reporter for MLB.com. Read Beck's Blog and follow him on Twitter @beckjason. This story was not subject to the approval of Major League Baseball or its clubs.