Declan Rice has revealed he has been managing nerve pain in a hamstring since Christmas as he reflected on the “obscene” amount of matches he has played this season.

The England midfielder sparked concern when he was forced off in the 72nd minute of the 4-2 World Cup win over Croatia last Wednesday. The problem relates to the upper hamstring, with the pain radiating into his lower back. But Rice described his substitution as “smart” and said he would be fighting fit for England’s second group game against Ghana in Boston on Tuesday.

“I’m ready and fit, raring to go,” he told ITV Sport. “I was feeling a little bit of neural pain in my hamstring, which I was managing from after Christmas with Arsenal for a very long time. Obviously, not a lot of people would have known that. It was all behind-the-scenes stuff but it was a smart decision.

“In the end, that last 20 minutes is probably where you pick up the most, and it’s where you play a 70-minute match. But that last 20 is where you really feel your body going for it. And I think it was a smart decision because the last few days I felt really, really good.”

Rice has played 63 matches this season, 55 for Arsenal and eight for England. His club reached the finals of the Champions League and Carabao Cup, losing to Paris Saint-Germain and Manchester City, and won the Premier League.

“It’s an obscene amount of games,” Rice said. “The schedule was crazy but what can we do about it? You can’t sit and complain. We have to just get on with it for the moments like I had in the Premier League, winning that Premier League. You know you’d play as many games as possible to have that feeling again and knowing that there’s a World Cup at the end of it as well. You know you’d put your body on the line to be always in to play. It’s a lot of games but we’ll get our break at the end.”

Declan Rice says the England players have been conditioning to adapt to the heat. Photograph: Bradley Collyer/PA

England began a hot-weather acclimatisation camp in Florida at the start of June and know the heat and humidity in North America are among the major challenges. The Croatia game was played in Dallas’s domed, air-conditioned stadium, where the temperature was set at 22C. Happily, it is forecast to be something similar in Boston’s open-air stadium for the 4pm local kick-off (9pm BST). It is likely England will play in much hotter conditions after that but Rice said the players have been reassured by Thomas Tuchel that they have the conditioning to cope.

“The heat’s going to dictate [our playing style] in spells but the manager’s been really clear with us and with this squad that we have the strength and power to outrun and outplay teams with our strength,” Rice said.

Declan Rice player profile

Rice also talked about the fitness worries that cling to Bukayo Saka, his Arsenal and England teammate. Saka has been managing an achilles problem for some time and was fit enough to play only as a 72nd-minute substitute against Croatia. He was good when he came on and set up the fourth goal for another replacement, Marcus Rashford. Saka followed an individual training programme on Saturday and is not expected to be ready to start against Ghana. Noni Madueke is likely to continue on the right wing.

“Bukayo will impact this tournament,” Rice said. “It’s really good the way we’re managing him. I think the amount of football he’s played – I’ve seen him at Arsenal – this little achilles problem he’s got. I think we’re managing him the right way, for sure.

“I don’t think you want to put him in straight away and put him at risk. We need to keep building him in. He’s been training really well. He came on and had an amazing impact the other night. He’s one of the biggest game players I’ve played with and he wants to play every game. But here he’s being smart. And we also have Noni who, for me, has been unbelievable.”

William Saliba is another Arsenal player who has pushed himself through the pain barrier this season. The France centre-half, though, continues to do so as he chases World Cup glory.

“I’ve had some minor niggles for several months,” he said in advance of Monday’s game against Iraq. “I’ve been gritting my teeth because there was the Champions League and the Premier League. But the coaching staff are handling it very well. The World Cup comes round only once every four years so you’ve got to grit your teeth. I’m not at 100% but there are plenty of players who aren’t at 100% either – you can’t make excuses.”