Young goalkeeper Bishop left Southend for United on deadline day last month.
He told manutd.com: “I loved my time at Southend. I played 39 games for the club and they're an incredible little club and they've got a lot going for them definitely.
"They looked after me, their fans looked after me and it got hard at times, but I definitely would not look back on it negatively because everything the club did for me and the people inside it was just positive. It was brilliant to play in League One."