UCLA lures top USC prospect —  then loses one to rival

UCLA lost a coveted defensive prospect to USC on Thursday after stealing one from the Trojans.

Defensive end Abdul-Malik McClain and linebacker Bo Calvert traded places in the recruiting rivalry on the first day of the early signing period after having previously pledged to play for their new nemesis.

McClain, who had 18 sacks last season for San Juan Capistrano JSerra High, signed with USC after having long been committed to UCLA. Calvert, who missed half of his senior season at Westlake Village Oaks Christian because of a broken leg, signed with UCLA after having said he would attend USC.

The switcheroo prompted widespread speculation on the teams’ respective message boards about who landed the better player; both were listed as four-star prospects on the five-star scale used by 247Sports.

Calvert retweeted a highlight video made by the official UCLA football Twitter account welcoming him to Westwood. Meanwhile, McClain thanked the Bruins and the other schools that had recruited him.

“But, I can only choose 1,” McClain wrote on Twitter. “I have chosen to spend the rest of my life as a Trojan!!”

UCLA also made what amounted to a recruiting swap with California.

The Bruins completed one of the nation’s biggest signings — literally — when they received a letter of intent from Atonio Mafi, a 6-foot-3, 360-pound defensive tackle from San Mateo Serra who had previously committed to the Golden Bears. UCLA’s efforts to land Mafi were bolstered by the arrival of defensive coordinator Jerry Azzinaro, who spent last season as Cal’s defensive line coach.

Cal signed Aaron Maldonado, a defensive tackle from La Puente Bishop Amat who had been committed to the Bruins.

UCLA also signed safety Stephan Blaylock of Bellflower St. John Bosco, receiver Chase Cota of South Medford (Ore), receiver Kyle Phillips of San Marcos, tailback Kazmeir Allen of Tulare Union, offensive tackle Alec Anderson of Rancho Cucamonga Etiwanda and receiver-defensive back Bryan Addison of Gardena Serra.

Bruins coach Chip Kelly is scheduled to speak with the media about his first recruiting class on Thursday morning.

UCLA EARLY SIGNINGS

Football players signing letters of intent with UCLA on Wednesday, the first day of the NCAA’s early signing period :

Bryan Addison WR 6-5 180 Gardena (Serra)

Kazmeir Allen RB 5-10 185 Tulare (Tulare Union)

Alec Anderson OL 6-5 283 Rancho Cucamonga (Etiwanda)

Bo Calvert LB 6-4 218 Westlake Village (Oaks Christian)

Chase Cota WR 6-4 195 Medford, Ore. (South Medford)

Atonio Mafi DL 6-3 360 San Mateo (Serra)

Kyle Phillips WR 5-11 176 San Marcos (San Marcos)

Go … or go for it?

Josh Rosen admitted that he’s intrigued by the possibility: What might he look like playing in Kelly’s offense?

“He’s a brilliant enough offensive football mind to where he can tailor his offense to the strengths of all 11 players, not just the quarterback,” Rosen said of the new UCLA coach. “ … He’s very forward-thinking and everything he does, he wants to know a reason why behind everything and just how to get the smallest of an edge on the football field.”

Rosen would give the Bruins a major advantage should he decide to return for his senior season. He said he’s met with Kelly “a few times” and would take his presence into account when determining whether to enter the NFL draft, where he would likely be a top pick.

Before he contemplates his future, Rosen hopes to lead the Bruins to a Cactus Bowl victory over Kansas State on Dec. 26 at Chase Field in Phoenix. He said he remained in the concussion protocol after being hurt late in the first half against Cal last month.

“We’ll see how it progresses,” said Rosen, who needs only 24 yards to edge Brett Hundley and become UCLA’s single-season passing leader. “I feel great. I mean, we’re not really hitting, but I feel great.”

Decisions, decisions

Jordan Lasley’s NFL stock is also on the rise after he became the first Bruin to amass 200 receiving yards in back-to-back games against USC and Cal. The junior, who received the team’s most valuable offensive player award at a team banquet, conceded that the increased buzz about his prospects has made him think about playing at the next level.

“I’ll be honest, it is hard to tune it out,” Lasley said, “because it’s been a dream of mine ever since I was 4 or 5 or 6 years old, ever since I was a little kid, I always knew I wanted to play football on the national stage in the NFL.”

ben.bolch@latimes.com

Follow Ben Bolch on Twitter @latbbolch