Jay Bruce is currently hitting .224/.306/.399 with isolated power (ISO) of .175 through the Reds’ first 97 games. These numbers fall well short of his career performance of .254/.328/.475 and ISO .221.

But in thinking about Bruce’s season, looking at it as whole oversimplifies the situation. Instead, it’s helpful to break it into (at least) two parts.

Bruce began the season with a knee injury. He played in 30 of the Reds’ first 31 games and hit .216/.352/.363 with isolated power of .147.

Jay Bruce ultimately decided his knee had worsened to the point where surgery was the prudent course of action. On May 5, he underwent an operation to repair a partially torn meniscus in his left knee. The Reds initially estimated Bruce would miss a month. Instead, at the end of his 15-day DL stint, Bruce was ready to return to the lineup. He was out from May 5 to May 22, missing 14 games.

In the 41 games since he returned, Bruce has hit .228/.276/.418 with an ISO of .190.

Those numbers are still short of his career benchmarks. Three points stand out.

First, Bruce’s ISO numbers show his power has substantially increased since returning from the surgery. He’s hit three home runs before and seven afterward.

Second, Jay Bruce’s walk rate has run a bizarre course in 2104. For context, his career rate of 9.6% is above the major league average (7.8%) and puts Bruce comfortably between the extremes of Joey Votto (15%) and Brandon Phillips (5.7%). In the first 31 games of the season, when his knee was bothering him, he walked an eye-popping 17.6% of the time. However, in the 41 games since he returned, he’s walked 5.5% of his PA, a rate much below his career norm.

Third, from the period May 23 to July 8, Bruce hit .244/.285/.463 with an ISO of .219. Other than the lower walk-rate, Bruce basically hit at his career level during that stretch of games. Since July 8, he’s been in a slump, with no home runs.