The Allies totally lost contact with Napoleon's retreating army. Already on 4 February, Schwarzenberg started to become anxious about his left flank and began pulling Wittgenstein's corps to the south, away from Blücher. On 5 February, Russian General Michael Andreas Barclay de Tolly ordered Seslavin's force away to the extreme left flank without notifying Blücher. Over the next few days, the Prussian field marshal mistakenly continued to believe that Seslavin watched the gap on his left flank. At this time, Napoleon began to consider the possibility of moving against Blücher's army. The French emperor calculated that Marshals Claude Perrin Victor and Nicolas Oudinot with 39,000 troops would be able to hold off the cautious Schwarzenberg. Meanwhile, Napoleon gathered a strike force of 20,000 infantry and 10,000 cavalry and prepared to march against Blücher.