Suarez scored a hat-trick against Wigan on Saturday to move ahead of Robin van Persie in the race for the Premier League Golden Boot with 21 goals in 27 appearances.
|17/4||Liverpool are 17/4 with BetVictor to beat Spurs by exactly two goals on Sunday
"It should only be judged on his performance on the field and you can't fault Luis for that," Downing told reporters.
Suarez was suspended for eight games for racially abusing Patrice Evra last season and has also admitted to diving, which Reds manager Brendan Rodgers labelled "unacceptable".
"Obviously he's had things which have happened in the past, but he's got on with his football and does his job at the end of the day," Downing continued.
"It should be judged on how he plays and for me, that's all it boils down to. Nothing else should matter and for me, I think he's got a hell of a chance."