Ben Stokes top scored with a score of 101.
"I'd love to get to 100 ODI wickets", he added.
Moeen grew up opening, still perhaps his most natural deployment but one which is not possible for England at present.
"Little niggles, if you get rested for a game, someone comes in and performs and you could lose your place".
However, he showed discomfort when bowling as England sealed the series with a thrilling two-run victory.
But when he bowled just a handful of deliveries at gentle pace with his left knee strapped, it looked unlikely he would play today.
"We've got the team that is capable of (winning our next seven matches)", he said. It's a confidence thing as well.
Should England claim their second win in four days they will take a 2-0 win in the series and will clinch the series.
England have begun this series with increased security measures promised around the match venues after Monday's terror attack in Manchester. "It would be fantastic to win a big tournament, and in England I think we've got a massive chance with this squad". "Hopefully it will go away".
"I had a hack really with the first two - and then the last one, I was pretty pleased with ..." he said of his success against Tahir.
"He played as a batter for us about a year ago when the same injury crept up". He's crucial to our campaign, so hopefully we'll have a fit Ben Stokes for the Champions Trophy. "I had a chat with him, and he helped - and I felt in a good rhythm going into this match".
However, former England off-spinner Graeme Swann said the hosts would be "crazy" to take a risk on Stokes.
They were even considering playing Stokes as a specialist batsman if he was unable to bowl.
Morgan lived dangerously too, escaping half-chances for caught-and-bowled by Pretorius and caught-behind off Andile Phehlukwayo on 16 and 22 while a direct hit from cover would have run him out on 24.