The Ultimate Fighter (TUF) 7 winner, Amir Sadollah, has been injured in training and will be unable to take on Jorge Lopez in a welterweight fight that was planned for UFC 143 at the Mandalay Bay Events Center in Las Vegas, Nevada, on Feb. 4, 2012.

Ultimate Fighting Championship (UFC) today made the announcement, as well as named his replacement, Matt Riddle:

TUF 7 winner Amir Sadollah has been injured. Stepping in to face Wanderlei-Silva trained striker Jorge Lopez will be welterweight Matthew Riddle. Verbal agreements are in for this matchup. Riddle was slated to scrap at this past weekend's UFC 141, but forced to withdraw at the zero hour due to illness.

Riddle was an eleventh-hour scratch from the UFC 141 fight card on Dec. 30, 2011, because of an undisclosed illness that had him "too sick to fight" Luis Ramos at the MGM Grand Garden Arena in Las Vegas, Nevada. As a result, the fight was scrapped altogether just before showtime and neither man competed that night inside the Octagon.

Riddle, also a TUF 7 alum, is still out to snap a two-fight losing skid, dropping unanimous decisions to Sean Pierson and Lance Benoist, respectively, in his most recent performances. He kicked-off his professional mixed martial arts (MMA) career with an impressive record (5-1) with the promotion.

However, "Monster Mash" -- who has been a mainstay in the 170-pound division since 2009 -- needs to turn in a solid, perhaps evening winning, performance against Wanderlei Silva's 23-year-old protege if he intends to stick around in 2012 and beyond.

Lopez, a Wand Fight Team member, struggled in his promotional debut, losing a unanimous decision to Justin Edwards at UFC Fight Night 15 back in Sept. 2011. "Lil Monster" has finished nearly half the opponents (five) who he has faced thus far in his young professional career via (technical) knockout and has never been stopped early.

With welterweight champion Georges St. Pierre injured, UFC 143 will feature an interim title fight between Stockton bad boy and former Strikeforce king, Nick Diaz, taking on Carlos Condit for 170-pound supremacy while "Rush" rehabs from knee surgery.

In addition, former welterweight number one contender Josh Koscheck will try to keep his spot among the division's elite by taking on the venerable Mike Pierce.

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