Fletcher, who made his return after missing a month of action through injury, was at the centre of a controversial - and potentially costly - incident as he was clearly tripped inside the CSKA area, only to be booked for diving.
United manager Sir Alex Ferguson described the decision as the worst he'd ever seen.
"It's a penalty," Fletcher insisted on MUTV. "I turned in the box and the lad just took my feet. I didn't try to fall, he just swept me. When the referee blew his whistle I thought, great we've got a penalty and then he started walking towards me with a yellow card - I couldn't believe it. Hopefully my luck [with cards] will change in the latter stages!
"It's nice to be back. I've not played for a while and there's always a few cobwebs in your first game back. But I felt fine in terms of the injury and my fitness. My overall sharpness and touch isn't there just yet, but that game will certainly help."