The 24-year-old Nelson (11-0) extended his undefeated streak last month when he defeated Jorge Santiago via unanimous decision. As a result, "Gunni" is now 2-0 in the UFC.
Meanwhile, Pyle (24-8) has quietly put together a three-fight winning streak since losing to Rory MacDonald at UFC 133. He stopped Ricardo Funch at UFC 142, knocked out Josh Neer at UFC on FX 3 and most recently stopped James Head at the TUF 16 Finale in December. All three wins came in the first round.
UFC 160, headlined by Cain Velasquez vs. Antonio Silva 2, will take place at the MGM Grand Garden Arena on Memorial Day weekend.