Neutrophils phagocyte necrotic debris and release cytokines, enzymes and oxidative factors. In the present study, we investigated the contribution of neutrophils to muscle injury, dysfunction and recovery using an unloading/reloading model. Mice were submitted to 10 days of hindlimb unloading and were transiently depleted in neutrophils with anti-Ly6G/Ly6C antibody prior to reloading. Leukocyte accumulation and muscle function were assessed immunohistologically and functionally in vitro. In addition, soleus muscles submitted to unloading/reloading were incubated in vitro with lipopolysaccharide (LPS, 100 µg/mL) to determine whether exogenous stimulus would activate neutrophil response and produce extensive muscle damage. Contractile properties were recorded every hour for 6 h and muscles were subsequently incubated in procion orange to assess muscle damage. Neutrophil depletion did not affect the loss in muscle force nor the time of recovery in atrophied and reloaded soleus muscles. However, atrophied and reloaded soleus muscles that contained high concentration of neutrophils experienced a 20% greater loss in force than atrophied and reloaded soleus muscles depleted in neutrophils following in vitro incubation with LPS. Procion orange dye also confirmed that neutrophils induced a 2.5-fold increase in muscle membrane damage in the presence of LPS. These results show that neutrophil infiltration during modified mechanical loading is highly regulated and efficiently eliminated with no significant muscle fiber injury unless the activation state of neutrophils is modified by the presence of LPS.