EAST LANSING, Mich. — Whenever U. Notre Dame’s offense was moving Saturday, it seemed sophomore receiver Theo Riddick had a hand in it.

Riddick, who totaled four receptions for 16 yards in Notre Dame’s first two games, led all players with 10 receptions and 128 yards at Michigan State U.

His 15-yard touchdown reception in the third quarter, which tied the game 21-21, was the first score of his career.

“He broke out,” Irish coach Brian Kelly said. “He’s an exciting player. We knew that he was going to be able to add to our offense. It was just a matter of time.”

Riddick, who spent his freshman year as a running back and transitioned to receiver in the spring, opened the season on top of the depth chart at the slot position. But he caught just two passes against Purdue, with a long of seven yards, and two more against Michigan with a long of three yards.

“[Those games] weren’t frustrating at all,” Riddick said. “Just a learning experience.”

Against Michigan State, Riddick’s longest catch was a 24-yarder in the third quarter, which brought the Irish to the Michigan State 10-yard line and set up a Kyle Rudolph touchdown on the next play.

Riddick was involved in all but one of Notre Dame’s scoring drives.

“That’s what we’ve been seeing out of Theo every day in practice,” Rudolph said. “I kept telling everybody, ‘We’ll see that on Saturday one of these weeks.’ He really came out and played well today.”

Riddick said the offense didn’t stray far from the original game plan, but some of his catches resulted from junior quarterback Dayne Crist finding him unguarded in the Spartans’ zone defense.

“They just gave me opportunities,” he said. “I would say my number was called more, but at the same time I was open a lot also.”

Michigan State’s defense concentrated mainly on Rudolph and junior receiver Michael Floyd, who had 80 and 81 receiving yards, respectively. That made Riddick an easy third option.

“Now he gives us that third weapon we had been looking for to balance off Rudolph and Floyd,” Kelly said.

Though Riddick caught six passes for 43 yards as a freshman, including a long of 16, he had struggled to be at ease in his new role.

“I guess the game showed I was very comfortable,” Riddick said. “Finally getting used to my position.”

He said he never doubted the switch, however.

“I always thought I could do it. That’s why I moved to this position,” Riddick said.

But in a way, Riddick isn’t through with his old position. He used his running back skills to evade defenders in open space on more than one carry, often turning a short pass into a long play.

“Once I got the ball in the open field I turned into a running back,” Riddick said. “Before the play I’m a wide receiver. After the catch I’m a running back.”