Ji-sung Park and Fabio are both set to be in the stands with QPR this Saturday instead of playing on the familiar Old Trafford turf, due to injury and ineligibility respectively. But both men are still in the United manager's thoughts after their moves to West London - permanent in Park's case, and for a season-long loan where Fabio is concerned.
"The great thing about Ji-sung Park is he's one of the best professionals we've had here," Sir Alex told ManUtd.com.
"He was truly fantastic, and particularly in big games. I loved playing him in the big games. His record against Arsenal, for instance, was fantastic."
This week's performance of Andrea Pirlo for Juventus against Chelsea also brought to mind some of Park's best displays for the Reds.
"The Milan games over there and at Old Trafford, when I asked Park to play directly against Pirlo, are memorable. He never gave Pirlo a kick and he kept running off him which was brilliant too.
"Park had roles that only a disciplined and selfless player could have. That’s exactly what Ji-sung was, selfless. He played for the team and whatever role you gave him, he would stick to that role. So he was a really wonderful, disciplined professional for us."
Fabio remains a current United player, of course, and while his brother Rafael seems to have raced ahead of him with his form for the Reds this season, the boss believes the pair could show parity again in the future.