DEERFIELD, Ill. — January sales figures underlined the impact of Walgreen Co.’s loss of Express Scripts Inc.’s prescription business, but the numbers did not dismay all analysts.

Moreover, Walgreens’ executives got some welcome validation of their contention that not all pharmacy benefit plans will want to be part of Express Scripts’ restricted network.

After meeting with the chain’s chief financial officer, Wade Miquelon, William Blair & Co. analyst Mark Miller maintained his “outperform” rating on the stock and declared in a research note that he believes Walgreens will be able to recoup business via other pharmacy benefit managers (PBMs).

That view won some support when the state of Nebraska recently announced that it is switching to United HealthCare as the provider for its state employee health benefit plan. As a result, Express Scripts will no longer be the plan’s PBM, and employees will once again be able to fill their prescriptions at Walgreens beginning July 1.

According to an Associated Press story, Carlos Castillo, director of Nebraska’s department of administrative services, said that more than half of enrolled employees had been filling their prescriptions at the drug chain until the rupture with Express Scripts.

“When that stopped at the end of December, it was a huge, huge change — and employees were very vocal about it,” he said in the article.

For his part, Miller had cut his earnings estimates for Walgreens last fall by 30 cents to $2.60 per share for fiscal 2012 and by 50 cents to $2.90 in fiscal 2013. Those reductions were based on the assumption that Walgreens would retain only 15% to 20% of the Express Scripts prescriptions, below Walgreens’ minimum expectation of 25% retention.

While recommending that clients buy both Walgreens and CVS Caremark Corp. shares, Miller noted that progress with Walgreens’ front-end initiatives is being overlooked.

“Walgreens’ front-end comp growth of 1.5% to 2% during the three months ended December was solidly above that of CVS during the comparable period,” he wrote. “The positive front-end momentum continued in January as well.”