Liverpool - Tottenham Hotspur boss Mauricio Pochettino believes his players might take a little longer to completely recover from their international exertions after they salvaged a 1-1 draw at Everton on Saturday.
Pochettino was happy with the second-half comeback that earned his side a point in their opening match of the Premier League season, yet a flat first-half display led to some tough talk from the Argentine at half-time in the visiting dressing room.
And Pochettino believes the lack of energy before the interval might well have been down to his players shaking off the effects of international duty during the close-season.
"We started the game slowly with a lack of energy and I am very disappointed with that," Pochettino said.
"We conceded the goal very early in the game and it was a big thing for us to manage that and difficult to recover the game.
"I was very unhappy with the first half and in the second half we played much better and we showed we looked like the team that played last season.
"We need to analyse what happened but in the end it is the first game of the season and there are a lot of things to do.
"We had a lot of players involved in the Euros and it is always difficult that they become fit and ready but I think in the end we need to take a lot of positives.
"In the end you try not to be too critical. It was my responsibility too and I tried to change things to change the score and create chances and win the game.
"We came very close to winning the game in the end because in the last 15 or 20 minutes we had control."
Pre-season signing Vincent Janssen gave Pochettino food for thought with a sharp second-half cameo that could further his claims to start next week at home to Crystal Palace.
But France goalkeeper Hugo Lloris is already a doubt for that game after limping off before half-time with a hamstring problem that was due to be assessed on Sunday.
Erik Lamela's 59th-minute header cancelled out a fifth-minute free-kick from Everton's Ross Barkley and denied new Toffees manager Ronald Koeman a winning start.
But the former Southampton boss was content with his side's efforts despite seeing them lose momentum after the break.
"First of all, I am happy about the team performance," Koeman said.
"I think the first 45 minutes was really excellent. We had good team organisation, we put a lot of energy in, and we were very dangerous up front.
"We had a big opportunity before half-time to score a second goal, and if we take that then it's a different game. Being one or two goals up is a completely different situation.
"We know it would be difficult towards the end because they have really good players, scoring players. But I think overall we worked very hard.
"Of course they had two big opportunities, great saves by Maarten Stekelenburg. That was important for us to keep the result, because it is also a mental question.
"But at least we showed what we like to see, and you could see the reaction of the fans, really supporting the team, and that is good to show today.
"This is the first game, but I am happy overall."
Romelu Lukaku did not figure for Everton amid speculation Chelsea will make a renewed bid to sign him, but Koeman insisted an ankle injury and not any impending transfer was responsible for the Belgian striker's absence.
Lukaku is expected to be available to face West Bromwich Albion at The Hawthorns next Saturday.