The Salford-born 20-year-old made his first start in the Champions League on Wednesday night and looked comfortable during the 4-0 victory over Dynamo Kiev which saw United qualify for the knockout stages with two matches to spare.
He could even have scored midway through the second half but saw his follow-up from Carlos Tevez's rebounded shot saved by Ukrainian goalkeeper Olexandr Shovkovskiy.
But it capped a stellar month for Simpson after he made his Premier League debut as a 30th-minute substitute in the 4-0 victory at home to Wigan on October 6 and then came off the bench for the 4-2 win in Kiev a fortnight ago.
"It is everything to get a start. It gives you that confidence that he (Ferguson) trusts you," said Simpson, who was loaned out to Sunderland for their Coca-Cola Championship-winning run-in last season having previously spent time at United's feeder club, Royal Antwerp, in Belgium.
He and Spanish centre-back Gerard Pique, also 20, were both given starts against Kiev while Jonny Evans, who was on loan with the Black Cats with Simpson, came on as a late substitute.
And Simpson believes Ferguson's keenness to develop young talent can only bode well for the trio.
"When he (Ferguson) said 'You and Gerard are playing at the back with Nemanja (Vidic) and Patrice (Evra),' it was a hell of a compliment," he said. "He didn't even have to say anything to me - just, 'Go out there and do what you normally do.'
"I was a bit gutted I didn't score but the young lads who played, me and Gerard at the back, we kept a clean sheet and we played some good stuff.
"The gaffer has always said if there is a young lad he will give them a chance and last night I proved that.
"After that he might feel, now that we are through, why not give me another game against better teams.
"For the likes of myself, Gerard and Jonny Evans it is looking good for the future."