The UFC today announced a switch for their upcoming UFC on FOX 7 card, as up-and-coming featherweight Darren Elkins has agreed to step in on short notice to fight No. 2 ranked Chad Mendes on just one month’s notice. MMAjunkie.com was the first to report the change, which was later made official by the UFC. The opportunity for Elkins arose when Clay Guida was forced to pull out with an injury just last week, opening up the door for a featherweight to step up and fight Mendes. Mendes, who is one of the top featherweight fighters on the planet, has seen Hacran Dias, Manny Gamburyan and Guida pull out of fights with him in recent weeks. But Elkins, who is riding a five-fight win streak with his latest W coming over Antonio Carvalho at UFC 158, had the guts to take the fight, which is scheduled for April 20 at HP Pavilion in San Jose, Calif. Despite Elkins’ win streak, expect Mendes to open as a large favorite in this fight, perhaps -350 or even higher, although it’s possible the public comes in early on Elkins due to the hype behind the Indiana native. Johnson Flagged For Elevated Testosterone Levels Lavar Johnson was flagged for elevated testosterone levels following his UFC 157 loss to Brendan Schaub. MMAjunkie.com reported the news today after confirming the information with the California State Athletic Commission. It was not yet announced whether or not Johnson would be suspended. Johnson has lost two fights in a row after he won the first two fights of his UFC career. With a 2-2 record in the Octagon and the recent news that the UFC is planning on trimming its roster by 100 fighters, do not be surprised if Johnson is given him walking papers from the promotion in the coming days. Holobaugh In, Hettes Out Vs. Siler An injury to prospect Jimy Hettes has taken him out of his upcoming UFC 159 matchup against Steven Siler, and his replacement in the bout is former Strikeforce lightweight Kurt Holobaugh, who will be cutting down to 145 pounds in his UFC debut. UFC Tonight was the first to announce the switch for the UFC 159 fight card, which takes place April 27 at Prudential Center in Newark, New Jersey. It’s unfortunate news that Hettes, who, despite his loss to Marcus Brimage at UFC 152 remains one of the top featherweight prospects out there, is out of this bout, but the replacement fighter between Siler and Holobaugh should be just as good, if not better. Expect the line to be pretty close to a Pick ’em when the lines open, but it’s likely the public will come in on Siler early considering they are more familiar with him that Holobaugh, who only fought once in Strikeforce (a decision loss to Pat Healy).