Juan Mata has sent a warning to Manchester United ahead of the trip to Celta Vigo on Thursday night (4 May) after identifying Eduardo Berizzo's side as "one of the teams that play better football in Spain".
The Spanish international also expressed his frustration with the latest two blows of United after Eric Bailly and Luke Shaw suffered new injuries during the disappointing draw against Swansea.
Celta are currently sit in the 11th position of La Liga after suffering a 3-0 defeat to Athletic Club Bilbao on Sunday (30 April).
Yet, earlier in the season the Galicians knocked out Real Madrid from the Copa del Rey quarter-finals while also beat Barcelona 4-3 in La Liga.
Mata, 29, has thus urged his teammates not to take anything for granted when United visit Balaidos on Thursday night for the first leg of the Europa League semi-finals.
"First of all we have to visit Celta in the Europa League. I can say, without exaggerating, that they are one of the teams that play better football in Spain, and not only this season," the United star wrote in his weekly blog.
"Being back home will be special, but very difficult at the same time. We must perform at our best in order to beat them. Besides, a few days later we will visit another big opponent such as Arsenal, with three key points at stake. Every game from now on is a final for us, that's how we face them."
Mata is expected to be available to face his compatriots after the Spaniard already made the squad during the weekend's draw against Swansea – having been on the sidelines since 19 March due to a groin injury.
However, José Mourinho could be without a number of key players after Bailly and Luke Shaw were forced off against Swansea, joining the likes of Zlatan Ibrahimovic, Marcos Rojo, Chris Smalling, Phil Jones and Tim Fosu-Mensah in the treatment room ahead of the trip to Celta.
"This week we're having a mix of good and bad feelings once again, the latter being, of course, the draw against Swansea and Luke and Eric's injuries," Mata said. "In this regard, we're being very unlucky, but we have to keep looking ahead. As for the game, we let two points slip away, again, when the win so much needed…"
"But there have been very good moments during the week as well, such as my being back with the team, and also my birthday. Thank you so much to all of you for your messages, it was a great day and, despite I didn't get the present of the three points, I hope we can have a great season ending in the remaining few weeks… As regards to my recovery, I'm very happy and looking forward to helping the team in such an important moment of the year, enjoying myself on the pitch and, hopefully, lifting another trophy."