Vidic has been out since the opening day of the season when he suffered a calf injury against West Bromwich, but after featuring for Serbia on Tuesday in a Euro 2012 qualification match, the United captain could be back in the side on Saturday.
"The big question mark is whether Vidic is ready," United manager Sir Alex Ferguson said at his pre-match press conference. "He had his first game for Serbia on Tuesday. It's certainly a consideration because he's such a great competitor. He came in yesterday and felt okay. But the Liverpool game is such an intense, stamina-draining game that you want everyone to be 100 percent so it might be more down to how he feels himself."
United owns a six-point lead on Liverpool entering the match, and if Vidic is unable to go on Saturday, it will once again be down to the youthful trio of Phil Jones, Chris Smalling and Jonny Evans to take his place.
Liverpool boss Kenny Dalglish will have a full side to choose from with the return of captain Steven Gerrard, who has featured as a substitute in the club's last three games and enjoyed some time to rest over the international break.
Gerrard is now in line for a starting place for the first time since March in a loaded midfield that also includes summer signings Stewart Downing, Jordan Henderson and Charlie Adam.
"We're in a fortunate position but a difficult one as well, but then you're better having more players to choose from than not enough," Dalglish said. "Every single one of them would be deserving of a spot but the more people there are to pick from, the more people are going to be upset!"
Liverpool has not lost to United at Anfield since 2007, and the Reds will be looking to extend their current winning streak to three games in an effort to close the gap at the top.
Manchester City enters the weekend level on points with United at the top of the table and the Citizens host an Aston Villa side that is unbeaten through seven games this term.
Chelsea is sitting only three points back of the two Manchester sides and hosts Everton, while surprise package Newcastle aims to keep its place in the top four with a home win over Tottenham.
Norwich City and Swansea City meet up at Carrow Road with the two promoted clubs level on eight points in the middle of the table, while QPR hosts a Blackburn side that is second from the bottom after two successive defeats.
Stoke City and Fulham have combined for only three wins in 14 games and they square off at the Britannia Stadium, Wigan tries to snap a four-game losing streak with a home win over Bolton, which has lost its last six, West Bromwich and Wolverhampton do battle at The Hawthorns and Arsenal tries to improve on its 15th-placed position with a victory over Sunderland.