Barcelona boss Ronald Koeman said his side's current form bodes well for next week's Champions League tie against Paris St Germain.

The Catalans turned in an impressive display in a 5-1 rout of Alaves on Saturday and Koeman said they are building momentum in time for Tuesday night's round-of-16 clash at Camp Nou.

"The team is doing well," Koeman was quoted by Marca. "We're confident we'll be able to win the tie (against PSG), knowing that we played against a strong defensive unit (in Alaves).

"They have injuries, but so do we. The tie is evenly matched. We have to play well to go through.

"We're in a good run of form, with a good streak of wins. We're confident."

Lionel Messi marked his club record-equalling 505th appearance with two goals against Alaves, while there was also a double for Francisco Trincao on his first LaLiga start.

Junior Firpo added a fifth goal late on as Barca made it seven straight league wins.

"Messi is very important," Koeman said. "He's in fantastic form. We know he's decisive – he has been for a long time.

"He's very focused. He's happy. He's effective. With him, everything is easier."

Teenage midfielder Ilaix Moriba made his LaLiga debut and laid on Francisco Trincao's first goal in an impressive first half.

But the 18-year-old was at fault for Luis Rioja's goal for Alaves early in the second period.

"It's important that he's being critical," Koeman said after Moriba had apologised for his mistake.

"He misplaced a square ball that you can't misplace. He has to improve."

Moriba expressed his "dream" of playing alongside his idol Messi during the victory.

"I'm always thinking about the last thing and I have that mistake in my head," Moriba said. "But I had a good game, I'm happy to have helped with the assist and I'm very happy.

"I was picking up my head and seeing Leo (Messi) and (Antoine) Griezmann – it was all a dream. It was all brilliant.

"(Messi) is lots of players' idol. Everyone that knows something about football knows that he's the best in the world and I'm thankful for the passes he gave me.

"I'll remember everything. I'll never forget anything. All I need now is to be able to play in front of the fans, with them here cheering us on."