Kevin Kampl described team-mate Dayot Upamecano's red card against Paderborn as "completely unnecessary" after RB Leipzig were held to a frustrating 1-1 draw.
Upamecano received a second booking two minutes before half-time on Saturday when he kicked the ball away in frustration after being adjudged to have fouled Streli Mamba.
Leipzig were in front at that stage after Patrik Schick's opener but bottom-of-the-table Paderborn ultimately claimed a dramatic point when captain Christian Strohdiek struck in the 92nd minute.
"It was completely unnecessary," Kampl said to Sky Germany about defender Upamecano's sending off.
"We lead 1-0, have the game under control and then we weaken ourselves.
"This is extremely bitter. A win would have been a huge step towards the Champions League.
"We are most annoyed about the goal in added time. Paderborn played well in the majority of the game - but we can no longer let the game get out of our hands."
Leipzig have now drawn five of their last six Bundesliga home games and have 11 top-flight draws in total this season.
Those dropped points have left them third in the table and involved in a scrap to secure a top-four finish, rather than competing with Bayern Munich for the title.
"We can be happy that the competition has also left us with some points - that's the only positive thing," added Schick, referring to Borussia Monchengladbach and Bayer Leverkusen losing to Freiburg and Bayern respectively.
The striker added: "Of course we are just really disappointed after the late equaliser. When we play in Hoffenheim next there is only one option - three points.
"We are still in pole position to reach the Champions League and have to give everything for this goal in the next few weeks."