Morgan Stanley's Discover Financial Services unit may struggle to gain more acceptance among merchants and higher transaction volumes after its spinoff, financial publication Barron's reported in its July 2 issue.

In its article about Discover, scheduled to be spun off on June 30, Barron's noted that the company lags its giant rivals on nearly every metric and suffers from limited merchant acceptance relative to the plastic-payment sector's top guns.

Barron's said that Discover shares, like its fundamentals, are apt to come up short.