The South Africa-born forward, farmed out on loan to Lincoln last season, was the outstanding player in a high-quality npower Championship encounter, crashing a 20-yard shot on to the crossbar in the first half and giving the Doncaster back four a torrid time throughout.

Despite the lack of goals, both sides served up eye-catching football, with Doncaster responding by hitting the woodwork themselves through Dean Shiels' superb curling effort soon after Somma's rocket had ignited the first half.

Grayson, who made five changes after Tuesday night's miserable 5-2 defeat at Barnsley, said fans would "have to wait and see" whether Somma would be lining up against Sheffield United in his side's third straight all-White Rose affair on Saturday.

"They have done themselves no harm in terms of keeping a clean sheet and the players that came in to the advanced areas of the pitch looked very comfortable and were a threat all night," said Grayson.

"Any time you make changes and give players the opportunities to come in, I'm always open for them to keep the shirt and there were some good performances tonight."

Somma, who arrived at Elland Road in September 2009 following his release from San Jose Earthquakes in the United States, had scored four goals in as many appearances this season - mainly after stepping off the bench.

He was denied by two excellent saves from former Leeds goalkeeper Neil Sullivan when through one on one in either half, but Grayson was delighted with his contribution.

Grayson added: "Normally with any chances he gets, he takes them. We see that in training and in the games so far this season, he goes through and he finishes them and he'll be disappointed, but at least he was getting into those positions.

"For him to have his first league start and put in the performance he did, he looked very assured.

"His hold-up play was good, his movement was good and on another night he could quite easily have had a couple of goals."

Doncaster passed up the chance to move second in the table, but manager Sean O'Driscoll was more than happy with his side's return from three games in six days.

O'Driscoll said: "I'd have taken being unbeaten over the last three games, to be fair.

"We could have won it, could have lost it. The game was quite open and you've got to give credit to Leeds for that.

"We were worried they would come and shut up shop after shipping five goals, but they were as open as they could be.

"He changed his team a bit and dropped his captain (Richard Naylor) and that was brave so you've got to give Simon credit.

"But I'm pleased because that's as complete a performance as we've had this season.

"We maintained the consistency and our organisation and discipline were good."