At the end of the day you need players like Lingard. He cost the club nothing, his wages won't be extortionate, he loves the club, and he is capable of putting in a quality performance.
He is not consistent, he is not world class but he's also not the finished product which gives him some room for error in repsects to poor performances with us. As long as he trains well and produces the odd moment of magic during games then he will be here for the long term, unless he desires regular first team football.
The only thing is we will have to accept that he is likely to put in an average performance here and there, and thats part and parcel of being a back up player. You're back up for a reason, ultimately you're not good enough. So we have to stick with him through the good and the bad. Fletcher, Wes Brown, O'Shea, Phil Neville... we've had them over the years, and how crucial they had been at times despite them having prolonged periods of poor performances from time to time.