Jose Mourinho admitted Manchester United defender Eric Bailly had been naive to allow himself to be baited into the red card against Celta Vigo that rules him out of the Europa League final.

Bailly was sent off along with Celta's Facundo Roncaglia after a bout of pushing and shoving involving players from both teams in the final minutes of the 1-1 semifinal second leg draw at Old Trafford.

The Ivory Coast centre-back will be suspended for the final against Ajax in Stockholm later this month, leaving United manager Mourinho to grumble about Roncaglia's provocation and his player's needless reaction.

"I didn't see the red card incident but Eric Bailly was phenomenal. The game was emotional for everyone. Some kept control better than others," Mourinho said.

"Facundo Roncaglia is not new in these situations, Bailly was probably naive. We now lose a very important player for the final, and we don't have many."

Holding a 1-0 lead from the first leg, United opted for a cautious approach that saw Celta dominate possession for long periods.

United snatched the lead through Marouane Fellaini's first half header, but Roncaglia equalised and, after Celta almost won it late on, Mourinho conceded his team once again lacked a cutting edge.

"We were the best team in the first leg but we never kill, we never score goals related to the chances we have," he said after the 2-1 aggregate victory.

"Celta were completely free of responsibility and gave us a very hard match. We suffered until the end and it was open until the last second.

"The boys gave everything they had. I'm really pleased for them."

United will qualify for the Champions League if they beat Ajax and Mourinho added: "After 14 matches we are in the final. If we win the Europa League I'm more than happy. It would be amazing."