"In anticipation of Jim Thome's historic 600th career home run, which will ensure his entry into the Baseball Hall of Fame, the Twins have directed Target Field staff to be on alert in the stands.

A handful of staffers have been placed in right-field and right-center field locations to either retrieve the prized baseball or make whoever catches it a trade offer so the left-handed-swinging Thome can have the keepsake.

Generally, a spectator who ends up with a Thome home run ball at Target Field this season is escorted to the Twins' clubhouse to meet Thome, has a picture taken with him and receives a bat or other memorabilia signed by him in exchange for the ball.

Thome has 598 home runs. Estimates vary on the worth of a Thome No. 600 home run ball. One local expert estimated it at about $4,000. Heritage Auctions in Dallas estimated the value of the ball at between $10,000 and $20,000. Memory Lane in Tustin, Calif., estimated it at between $25,000 and $50,000. Steiner Sports Memorabilia of New Rochelle, N.Y., estimated the value at about $50,000.

Meanwhile, Dave Fradkin, a sports apparel entrepreneur from Southbury, Conn., was in Minneapolis on Tuesday to receive approval from Thome to promote "600 Thome Run Club" hats, which can be purchased for $25.25 (Thome wears jersey No. 25) at thomerunclub.com.

During a Twins on-field promotion before Saturday's game against

the Chicago White Sox at Target Field, one of the young participants fainted, hitting the ground hard. "