The 20-year-old has been heavily criticised for some of his displays this season, but despite this is the only United player to have appeared in every game of the campaign.
Sir Bobby told The Journal: "We've stuck with him. He has not been totally on top of his game in matches, but he does a lot of work for the side.
"He made mistakes earlier in the season. You either leave him out or you let him play through his bad spell, which is what we've done.
"I see every move JJ makes. I see it when he loses the ball and when he is hurried into making a pass, but I also see the prodigious work he does from box to box, the way he presses the ball and his ability in the air.
"I see the good things as well as the little errors. I stuck with him and he has come through it nicely."
Jenas seems to have been experiencing the same kind of second-season syndrome as many young players after establishing himself last year. Everton’s golden boy Wayne Rooney has been suffering in the same way, while Bolton’s Kevin Nolan is demonstrating admirably that young players can recover from this kind of dip in form.
One thing that Jenas has contributed plenty of is hard work, as demonstrated by his goal against Leicester where he was involved in the move inside his own half of the pitch before making up the ground to get on the end of Shearer’s cross.
The suspicion is that Sir Bobby would have rested the youngster at some point if Lee Bowyer had been available more regularly, but having persevered with him the manager is finally starting to see some rewards.
Last season Jenas’ first goal of the campaign triggered a run of seven goals in 17 games and a rich vein of form that earned him his first call into the England squad.
A repeat of last season would be very timely, both for the club and for the player, whose position in the starting line-up must be coming under some pressure, with Bowyer fit again and Kieron Dyer freed from his forward duties.