Friday means happy hour at Arlington Park, where fans start their summer weekends by kicking back with a late post at the Arlington Heights, Ill., track.Countless hours have been invested in getting a 4&#45;year&#45;old named Kopitar back to the races, so it remains to be seen whether it will be a happy one at Arlington this particular Friday for trainer Rusty Arnold and his staff. The culmination of those tireless efforts will come in the featured eighth race, a $44,200 second&#45;level allowance on turf that marks the first race in more than a year and a half for Kopitar.&ldquo;He&rsquo;s an extremely talented horse,&rdquo; Arnold said earlier this week from Saratoga, where he is personally overseeing one of his three divisions, the other two being at Churchill Downs at Keeneland. &ldquo;We&rsquo;ve put a lot of time into bringing him back the right way.&rdquo;Kopitar, owned by Green Lantern Stables, will ship from Keeneland as one of nine 3&#45;year&#45;olds and up in the Friday feature, which goes at about a mile on turf. Shane Sellers has the mount from post 8.After winning his career debut at the 2008 Keeneland fall meet, Kopitar won right back in a Churchill turf allowance. That form was so impressive that in his third start, on Jan. 17, 2009, he was the even&#45;money favorite in the Dania Beach Stakes at Gulfstream Park. He faded to sixth, but that wasn&rsquo;t the worst news. &ldquo;He came out of it with a bone chip that required surgery,&rdquo; Arnold said.Arnold said he brought back Kopitar the following autumn, &ldquo;but he had something bugging him a little bit, so we put him away again until the first of April.&rdquo; And after a lengthy series of workouts, here he is, finally ready to go.The return spot isn&rsquo;t that easy. Besides the obvious observation that opponents such as Voy Por Uno Mas, Sporty, Harlequin Sky, Mr. Mischief, and Tazz all have more recency, they also are in very good&#45;to&#45;decent form and appear poised to go through this second condition.Two other allowances also are on tap for Friday &ndash; a $41,480, first&#45;level turf route for fillies and mares (race 5) and a $31,500, first&#45;level main&#45;track sprint for Illinois&#45;breds (race 9). Twilight first post is 3 p.m. Central.