Southampton have been a brilliant cup team this season, knocking out opponents they would have been expected to go down to with great gusto and tremendous efficiency.
Arsenal were one of those teams to fall under the Southampton spell this season, when the Saints beat Arsene Wenger's side 2-0 in the EFL Cup. With Southampton now going on to the final of the tournament formerly known as the League Cup by beating Liverpool in the semifinals, they will be an extremely confident outfit when they take to the St. Mary's pitch against Arsenal in the FA Cup fourth round.
So, for Arsenal to beat this confident Southampton side, Wenger will need to put up a strong starting XI and make sure his team do not start as badly as they did in the previous round, against Preston North End.
While a few of the main men could be rested, Wenger admitted he will play with a team largely made up of senior first-teamers – Alexis Sanchez, Mesut Ozil and Laurent Koscielny are the likely players to be rested – with one player in particular ready to make a long-awaited start.
Danny Welbeck, who recently made a comeback from a serious injury, has not started for Arsenal since last April and considering the club have an English Premier League game to contend with on Tuesday as well, Wenger could very well give the England international a go from the beginning.
"He has a chance to start or to come on, yes," Wenger told the club's official website. "He looks sharp, he's worked very hard. Maybe it will be an opportunity for him.
"In training he still lacks a fraction of zip when he starts, but overall he looks quite fit. What is the most important is that he doesn't look scared. That's the biggest hurdle when you come back."
Theo Walcott makes a welcome return from injury, but Wenger will have to do without Granit Xhaka for the next four games, after the midfielder received a four-match ban for his straight red card, his second of the season, against Burnley last weekend.
Mohamed Elneny is with the Egypt team playing at the Africa Cup of Nations, while Santi Cazorla is still recovering from his injury. Per Mertesacker and Mathieu Debuchy returned to full training late this week, but they are unlikely to be considered.
Another face who will not be on the bench or touchline for this FA Cup match against Southampton will, of course, be Wenger himself, after the manager was handed a four-match ban for his reaction to being sent off late in the Burnley game. Wenger will be able to give messages while sitting, most likely, in the director's box, but he will not be able to come down to pitch level.
Southampton are coming off a testing match on Wednesday, when they beat Liverpool 1-0 in the semifinal second leg of the EFL Cup. Claude Puel has rotated his squad as much as possible throughout the season, so expect more changes to come in on Saturday.
Virgil Van Dijk, the centre-back, will miss out again with an ankle injury, while Jay Rodriguez and James Ward-Prowse are also ruled out after picking up knocks during that win over Liverpool.
Expected starting XI: Southampton: Fraser Forster; Cedric Soares, Jack Stephens, Maya Yoshida, Ryan Bertrand; Pierre-Emile Hojbjerg, Oriol Romeu; Nathan Redmond, Steven Davis, Dusan Tadic, Shane Long.
Arsenal: David Ospina; Hector Bellerin, Gabriel, Shkodran Mustafi, Kieran Gibbs; Francis Coquelin, Aaron Ramsey; Alex Oxlade-Chamberlain, Alex Iwobi, Lucas Perez; Olivier Giroud.