The organization is set for their second outing on November 5 in Moline, Illinois at the iWireless center with Arlovski and Penn making their returns.
Additionally, former UFC heavyweight champion Tim Sylvia (29-7) makes his organization debut against Pedro Rizzo (19-9).
There's no word as to why Grove isn't returning for the organization's second event.
Sylvia, who's had a rocky career since his exit from UFC, has now claimed victory in four of his past five bouts.
Rizzo is on a three-fight win streak that includes a decision victory over Jeff Monson and knockouts of Gary Goodridge and Ken Shamrock.
Arlovski, who snapped a four-fight losing skid at the inaugural ProElite event, faces 300-fight veteran Travis Fulton (247-47-10, 1NC).
The younger brother of UFC welterweight BJ Penn, Reagan (1-0), returns to action for his second professional bout against an opponent still to be determined.
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