Sam Johnstone
Simon Grayson is hopeful of keeping Sam Johnstone beyond the end of his current loan spellGetty

Preston manager Simon Grayson has admitted that the Championship clash with Brentford on 23 January could be the last match of Sam Johnstone's current loan spell, but claims he is in dialogue with Manchester United over hopes of securing a possible extension.

After helping his hometown club to secure promotion via the League One play-offs during a successful four-month stint last season, the 22-year-old returned to Deepdale in late December on a 28-day emergency deal. Such a signing came at a critical time for the Lilywhites, who had been forced to bid farewell to highly-rated England U21 goalkeeper Jordan Pickford after his fine run of 13 clean sheets in 27 appearances led to Sunderland exercising their early recall option.

Johnstone has yet to taste defeat in his three league matches back at Preston, with a credible 1-1 draw at Ipswich last weekend helping the Lancashire club to nestle neatly in mid-table and create a healthy 11-point buffer to the relegation zone. His initial loan agreement formerly had two games left to run, but Derby's involvement in the fourth round of the FA Cup means that the trip to the Ipro Stadium has had to be rearranged.

Asked by BBC Lancashire for an update on the player's future, Grayson said: "It [Brentford] could be his last game. Look, we're in dialogue with Manchester United all the time and we're trying to get some decisions and some answers but, as you can imagine, sometimes when you're dealing with the big clubs they've got more pressing things to deal with.

"I think Sam's made it clear that he wants to stay and wants to get some game time. He's fitted in very easily into the squad and done what he's needed to do. We want him to stay, we'll keep talking and talking to Manchester United and hopefully get a result from it whenever really."

Johnstone has yet to make a senior competitive appearance for Manchester United. He did feature during the club's pre-season campaign in the United States, however, starting against America and the San Jose Earthquakes before being used as a substitute against Barcelona and Paris Saint-Germain. He was also installed as back-up to Sergio Romero at the start of the season with doubts surrounding the respective futures of David de Gea and Victor Valdes.

"That's always been the case," Grayson added of a mutual desire for the player to return to Preston. "Even over the summer, it was clear that Sam wanted to come here and we wanted to bring him here but there's the bigger stumbling block of a football club wanting to keep their own player. That's what we suffered in the summer and we're in the hands of them at this moment in time.

"We've had plenty of dialogue with them over the last few weeks and I'm sure we will over the next few days. Next week as the window gets closer we'll try and do more and more work with them. But it's very difficult to tie certain individuals down at Manchester United to make an answer."