Cathcart has impressed since joining Blackpool from United.
“I saw the end coming at United,” he confessed. “I could have moved a year ago but that fell through and when the manager is prepared to sell you then you know it is probably right to move on.
“I did speak to Sir Alex and he said if I stayed, he would give me another chance but the 25-man squad ruling came in at a bad time for me so it made my decision a bit easier.
“Moving to Blackpool has given me a big chance of being in the Northern Ireland squad.
“No-one expected it outside the club, but it was a great result at Anfield. Obviously Liverpool are struggling a bit and we knew going to Anfield was always going to be difficult, but we did well.
“We were above them in the Premier League table before the game so we didn’t see any reason why we couldn’t go there and beat them, especially with the form they are in, not scoring many goals, whereas we have scored a few goals and it turned out well.
“If you look at our start, we have had five away games and two home games, so we still have all those home games to come which is going to be good for us.
“The manager knows what he’s talking about – there is definitely method to the madness.
“He does his research and he knows the way he wants.”
