7-Eleven Inc. is the new player on the block in efforts to take over Ankeny-based Casey’s General Stores Inc., the Wall Street Journal reported this afternoon, citing sources familiar with the offer. On Tuesday, Casey’s said an unnamed suitor had offered $40 a share in a “consensual transaction” to acquire the company. Casey’s said the price undervalued the company, but that it had agreed to enter negotiations.Canada-based Alimentation Couche-Tard Inc. has offered $38.50 a share in a bid that has been repeatedly rejected by Casey’s board. Also today, a federal judge in Des Moines denied Casey’s request for a preliminary injunction requiring additional disclosure in Couche-Tard’s $15 million cash-out of Casey’s stock on April 9, the day it made public its months-long effort to negotiate a buyout.