Such proved to be the case.

Napoleon soon penetrated his design, and strove to frustrate it by a rapid move from Vilna towards Polotsk on Barclay's flank, but he failed to cut into his line of march, and once more had to pursue.
Despite the heavy shrinkage in the Grand Army caused by a remorseless rush through a country wellnigh stripped of supplies, the Emperor sought to force on a general engagement.

He hoped to catch Barclay at Vitepsk.

"The whole Russian army is at Vitepsk--we are on the eve of great events," he writes on July 25th.

But the Russians skilfully withdrew by night from their position in front of that town, which he entered on July 28th.