Pennsylvania's Hollenback Field will be the site of one of the crucial encounters of the young collegiate baseball season when Harvard's hardball troops invade Philadelphia today for a doubleheader against the Quaker nine.

Penn coach Bob Seddon has twelve returning lettermen from last year's 19-12-1 squad, and hopes to repeat the 3-2 victory his team registered over a World Series-bound Crimson outfit early last season.

Among the proven Penn starters is Andy Muhlstock, upon whom many of Penn's hopes are pinned this year. Muhlstock is tabbed as one of the finest pitchers in the East. He racked up a 9-2 record with an ERA of 1.69 last season. Far from a slouch at the plate, Muhlstock also contributed to the squad's success with a .344 batting average--best on the team.

Ed Boone, an all-EIBL first baseman last year, is returning after a spectacular junior season in which he hit .327, and led the team in runs, doubles, home runs, RBI's and fielding percentage.

Old Reliables

The Quakers are also relying on third baseman-outfielder Don Valenzano, who led the squad in hits and batted .306 last year.

Newcomers backing up the Penn veterans are Glenn Partridge (.360 for the freshmen), Mike O'Connor (.433 for freshmen), and Graham Davis (.277).

The Crimson squad enters the important doubleheader minus the services of captain Jim Stoeckel, whose eligibility case will be reviewed next week.

"Penn has got to be the best team in the league this year," Crimson coach Loyal Park said Wednesday. Park will send Mike O'Malley and Milt Holt to the mound today for Harvard, hoping to add to the team's current 10-3 record.