Keates saw his side reach the Second Round for the first time since the 2015/16 campaign with goals fro Morgan Ferrier, Josh Ginnelly, and Zeli Ismail proving enough to make Larnell Cole's late strike nothing more than a consolation.
Speaking via the Express & Star, Dean said; "I think we could have made things a bit easier. We had a lot of chances and didn't really kill them off. I thought in the second half we broke well, we broke at pace. We scored a good couple of goals. But we would have liked to have made it more easier for ourselves."
The gaffer gave starts to goalkeeper Chris Dunn, on-loan West Brom full-back Kane Wilson, and midfielder Liam Kinsella, and was impressed as the trio entered solid displays, giving him something of a selection headache heading into this weekend's clash with Gillingham.
Keates continued; "I said in the dressing room, the three lads that came in were absolutely outstanding. The subs that came on contributed as well. It's good. It's a squad game and a group of 11 players isn't going to get us through the season. Whenever they get a chance to put the shirt on, whether it's a Saturday or a Tuesday, all they can do is the best for themselves and the best for the team. If they do that it gives me some decisions to make."
Dean also went on to praise summer signings Morgan Ferrier and Josh Ginnelly, the duo opened their goal-scoring accounts against Tranmere and have been superb since they arrived at Fortress Bescot, he said; "They have shown us what they are about in the first few games of the season. They are eager and they want to progress and they are at a club where they are going to progress. We are all going to go forward. It's still early days, we are happy with the performance at Tranmere and we'll get ready for Saturday now."