Here are some key stats to consider from this week's marquee games before selecting your UCL fantasy team.
Forwards
All eyes will be on Old Trafford on Tuesday as Manchester United will host Cristiano Ronaldo and Juventus. It will be Ronaldo's second trip there as a visiting player, and his first in over five years. In his lone trip as a visiting player, Ronaldo scored the goal that eliminated United from the Champions League in the 2012-13 Round of 16. He returns to Champions League action after missing his team's previous group stage match against Young Boys due to a red card. He'll be looking to continue the form that's seen him either score a goal or provide an assist in each of his last five matches.
However, if you're looking for a Tier 1 forward, it's hard to ignore Kylian Mbappe right now, even as PSG prepares to face a tough Napoli team on Wednesday. Mbappe is the hottest player in the world right now, with 11 goals and four assists in his last eight games, but he'll be facing one of his toughest tests yet against a Napoli side with four clean sheets in its last five matches.
If you were contemplating choosing Luis Suarez as Barcelona waits for Lionel Messi to return from injury, you may want to be careful. He has just one goal in his last seven games across all competitions, and he has just two goals from open play this season. Looking at Tier 2 and staying in that same Napoli-PSG matchup, you'll want to keep an eye on Napoli's Lorenzo Insigne. He's scored six goals in his last seven games for Napoli and his 17 percent shot conversion rate is 10th-best (minimum 25 shots) among all players in Europe's top-five leagues.
Midfielders
When looking over your Tier 1 midfielders, one I'd recommend staying away from is Manchester United's Paul Pogba. The dynamic midfielder is struggling to deliver fantasy (and actual) production under José Mourinho, scoring just one goal from open play across all competitions this season -- and he's only provided two assists. He's also facing a Juventus team that has conceded just 22.7 fantasy points per game to opposing midfielders, third-stingiest of any team from a top-five European league.
Real Madrid's Isco is a name to watch in Tier 2. He returned to the starting lineup for Real Madrid over the weekend in a 2-1 loss to Levante after having missed more than a month. He could be the key to bolstering Madrid's offense. The team will face Viktoria Plzen this week, which has already conceded seven goals in its two UCL games, including five in its last match against Roma. Isco's four chances created on Saturday were second-most by any player in the match and he completed 92 percent of his passes in the losing effort.
Defenders
It would seem hard to go wrong with choosing either of the Liverpool defenders available to you from Tier 1 -- Andrew Robertson or Virgil van Dijk -- as their opponent, Red Star Belgrade, has scored just once in its two matches, and is coming off a 6-1 defeat to PSG in Matchweek 2. Liverpool's defenders are averaging 47-plus fantasy points per game in the Premier League, third-best among all clubs, and both van Dijk and Robertson are averaging 10-plus fantasy points per game.
Goalkeepers
It's hard to look past Valencia's Neto as the play in goal for this week's Champions League games. He has clean sheets in both of his first two Champions League appearances this season and will be facing a Young Boys team that has yet to score a goal in this competition.