Sophomore Phil Bolster moved from end to tailback yesterday as Art Valpey scrimmaged his two platoons simultaneously for the first time this season in the mud at Soldiers Field. Valpey termed the practice session, "not very satisfactory."

In the contact work under the Stadium lights, he had his offense running against Henry Lamar's Freshmen, while at the other end of the same field, the Jayvees hammered away at the first-string defensive squad with a Holy Cross T attack.

Will Stay at Tailback

The switch of Bolster to tailback is permanent. Valpey announced. A 21-year old Sophomore, he has been rotating between third-string Varsity end and Jayvee tailback. He played halfback on the Freshman team last year, and will now operate behind Jimmy Noonan, Chuck Roche, and Jim Kenary.

With the possible exception of guard Sam Butler, injured in Saturday's Dartmouth game, the Crimson will be at full physical strength for Holy Cross--if. The if hinges on whether pre-meds Emil Drvarie, Walt Coulson, and Skip Garvey can avoid taking an all-day examination scheduled for Saturday. All three are supposed to show up for the tests, which are run by the medical school entrance boards. The afternoon portion is listed for 2 to 5 p.m., at precisely the time the Crimson linemen will be needed at the Stadium.

Their loss, coupled, with Butler's would weaken Harvard's defensive setup. Drvaric and Butler are defensive guards, Coulson plays at one of the defensive flanks, and Garvey operates at tackle on defense.

Coach Valpey disclosed yesterday that Team Guthrie, who has been running at third-string tackle this fall, has decided to abandon football. The former Notre Dame athlete has been hampered by severe oil burns, which hospitalized him last summer.