Receiver Damian Williams is cleared to play

It was difficult to tell who was happier Tuesday -- USC receiver Damian Williams or quarterback Matt Barkley.

Williams went from doubtful to probable for Saturday’s game against UCLA at the Coliseum, doctors clearing the junior to play after he tested his injured right ankle in practice.

“I didn’t do anything totally crazy, just try to see if I can cut and move and how fast I can run,” said Williams, who did not play in the Trojans’ 55-21 loss to Stanford. “Straight ahead, I’m fine. There’s a little discomfort cutting but not too much.”

The return of Williams, coupled with tight end Anthony McCoy‘s progression toward a return to full strength, would help Barkley and the Trojans offense immensely against a surging Bruins team that ranks first in the Pacific 10 Conference in scoring defense and turnover margin.

Barkley, who has passed for 11 touchdowns with 10 interceptions, has struggled for much of the last three games. On Nov. 14, he lost a fumble and had three passes intercepted during Stanford’s rout of the Trojans at the Coliseum.

Now the freshman faces a UCLA defense that features safety Rahim Moore, the NCAA leader with nine of the Bruins’ 17 interceptions.

“They play a pretty base defense, which is not going to be hard to see,” Barkley said. “They’re just going to play hard and get after you.

“So it’s not going to be too tough mentally. . . . They’re secondary is very impressive but, again, they’re beatable at times.”

Barkley has looked rejuvenated the last two days. He said last week’s practices helped get “back to normal.”

Barkley’s father, Les, played water polo for USC, so the quarterback knows the rivalry with UCLA, which also wooed him out of Santa Ana Mater Dei High. “I was heavily recruited by them and have been to their campus a bunch,” he said. “There were things I liked and things I didn’t like, just the same with a lot of schools that I visited.”

Barkley likes the thought of having Williams and McCoy on the field at the same time, which last occurred Oct. 24 against Oregon State.

Williams, who is a wearing a custom ankle brace and a wider right shoe to accommodate it, has caught a team-best 45 passes, five for touchdowns.

McCoy, who was sidelined for two games because of an ankle sprain and was not at full strength against Stanford, has 17 receptions and a touchdown.

“They’re both threats, they’re both All-American potential,” Barkley said. “Just their presence on the field adds so much to our offense.”

Guardedly optimistic

Offensive lineman Nick Howell worked with the first-team offense at right guard for the second straight day. The fifth-year senior started six games at right tackle in 2008 but has played as a back-up this season.

“I’m starting the week with the first team and I’m going to try and finish it on the first team,” said Howell. “It would be great to finish off these last games starting.”

Quick hits

Tight end Blake Ayles (knee) is not practicing and will not play against UCLA, Coach Pete Carroll said. . . . USC leads the series with UCLA, 43-28-7.

gary.klein@latimes.com

twitter.com/latimesklein