Boothe is a sixth-round draft pick from Cornell, McQuistan a third-round choice from Weber State.
While coach Art Shell stopped short of naming Boothe the starter for Oakland's next game on Oct. 1 against Cleveland, he praised Boothe's performance and conceded McQuistan has been struggling.
"All throughout training camp, Kevin's performance level has been growing," Shell said. "When he's in there, you know he's around because he's going to strike out. He has great feet, balance, things like that, so it's been a positive."
McQuistan was switched from left tackle to right guard during Oakland's last optional minicamp and was placed on the first team, with his aggressive style drawing comparisons to former Raiders Pro Bowler Steve Wisniewski.
"Paul is going to be an excellent player in this league," Shell said. "At times when you put a young kid in there, they're going to stumble a little bit. Paul just has to stay the course and he's doing that. His time will come. He's going to be a better player down the road for us."
Boothe's ascension comes as a surprise, given that he comes from an Ivy League school that plays a nine-game schedule against non-scholarship competition and has no spring practice.
A clue that Boothe was more than just a project to be kept inactive all season came in Week 1, when he was on the field in a power package at right guard with McQuistan moving to tight end.
In Week 2, Boothe replaced McQuistan in the fourth quarter.
"It was great to get the extensive playing time out of the way," Boothe said. "I played a few snaps the week before. It was good to get in there and kind of get the jitters out. Once I got out there, football's football."