Hooker Michael McIlorum was also a doubt for the derby fixture but is included.
It remains to be seen whether Tomkins and O’Loughlin recover in time, as coach Shaun Wane has not given up hope.
He said, “I’m expecting them to be pushing to play.
Jon Wilkin has guaranteed that Saints will ‘rip into’ Wigan when the two sides meet on Monday.
The utility back says the team owes the fans a performance:
“The Wigan game is big and is as big as they get for me.
“The week’s build up is special. When you bump into people they mention it and the press build it up too. The fans will turn up and just want us to win.
“They won’t be worried about league position or where we are at the end of the season. It’s about the game and I think the timing is right for us to come into this match.”
St Helens 19-man squad: Wellens, Turner, Meli, Hohaia, Lomax, McCarthy-Scarsbrook, Puletua, Wilkin, Manu, Laffranchi, Clough, Jones, Makinson, Greenwood, Walmsley, Thompson, Howarth, O’Brien, Richards.
Wigan 19-man squad: Charnley, Crosby, Dudson, Farrell, Flower, Gelling, Goulding, Green, Hampshire, Burke, Hughes, Mossop, McIlorum, Taylor, S. Powell, Richards, Smith, L. Tomkins, Tuson.
Prediction: Derby games can go either way and Saints need the win more than Wigan. Home win.
Super League summary:
St Helens won 27 (includes win in 2000 Grand Final & wins in 2000, 2002, 2009 and 2011 play-offs)
Wigan won 30 (includes win in 2010 Grand Final & wins in 2001, 2003 and 2004 play-offs)
St Helens highest score: 57-16 (MM, 2008) (also widest margin)
Wigan highest score: 65-12 (A, 1997) (also widest margin)