Lebese bagged his second goal in his fourth start for The Brazilians since his switch at the start of the season, before being replaced by Anthony Laffor at half-time.
Downs went on to suffer a 3-2 defeat at the Peter Mokaba Stadium, with Mosimane explaining that Lebese himself had asked to be substituted.
“Ja [the goal was a nice confidence boost], but he was not physically ready for the match. He struggled with his condition and he asked to be substituted,” Mosimane said.
“I asked him, and he said, ‘Look, I’ve got heavy legs and it’s a bit hot for me. I don’t have the condition [sic] for it.’”
While it is unknown whether the former Kaizer Chiefs winger will return to the side for Tuesday’s visit to Ajax Cape Town, Mosimane is left sweating over the absence of several other key figures.
“We’ll get a few guys back. At least we’ve got Anthony back, we’ll get ‘Vila’ [Sibusiso Vilakazi] back, but I don’t know if he’s ready for Tuesday,” added ‘Jingles’.
“Khama [Billiat] is still struggling with his injury also. Bangaly [Soumahoro] is also not available, Thapelo [Morena] has flu, we’ve now lost Anele [Ngcongca]. [Aubrey Ngoma] is also injured.”
Sundowns face a hectic schedule this month with further league clashes against Orlando Pirates, Platinum Stars and Kaizer Chiefs over the next three weeks.