Celtics backup guard Nate Robinson is ready for action -- and delivers

Nate Robinson is the Celtics’ little-used backup guard -- “little” being the apt term for his height (5-feet-9) and playing time, which hasn’t been more than 13 minutes this postseason.

He’s also their occasional spark, ignited every so often, namely Game 6 of the Eastern Conference Finals when he provided 13 points off the bench in the series clincher that sent the Celtics to the Finals.

On Sunday night in Game 2 of the NBA Finals, a 103-94 Celtics win, Robinson caught fire again, giving his team seven points in just six minutes during a tight fourth quarter.

He started the fourth with the score tied, 72-72, and replaced point guard Rajon Rondo, who had played all 36 minutes to that point and was “exhausted,” according to Celtics Coach Doc Rivers.

“Yeah, I needed it,” Rondo said of a breather.

At the 8-minute, 59-second mark, Robinson pulled up for a three-pointer at the top of the key that gave the Celtics the lead, 81-80. A steal by fellow Celtics guard Tony Allen on the other end led to a fast-break Robinson layup on the break 24 seconds later.

A few minutes later, he was fouled by Lakers center Andrew Bynum and converted two free throws.

Rondo replaced Robinson shortly thereafter, and continued his own brilliant night -- which ended in a 19-point, 12-rebound, 10-assist triple double -- but the spark had struck again.

“I thought the seven or six minutes that Nate Robinson played for us was huge,” Rivers said.

Said Rondo: “Nate played great. It’s the second time he’s done that this year. He was ready when his name was called.”

While there is still a question of whether he can be the bench contribution that James Posey was for the Celtics in 2008, it seems Robinson is starting to feel more comfortable in his role, even though he never knows when he’ll be asked to contribute.

Robinson’s mindset, then? “Stay ready always, be prepared,” the former Washington Husky said.

Robinson was perfect from the floor, making two free throws, a three-pointer and a layup for seven points in just six minutes. “I always feel like I’m hot, no matter how many I miss or how many I make,” Robinson said.

And then Robinson alluded to one of his teammates, shooting guard Ray Allen, who happened to set the NBA Finals record with eight three-point field goals in Sunday’s game.

“If I make one, I feel like I’ll make ‘em all, just like Ray,” Robinson said, smiling.

baxter.holmes@latimes.com