Monreal and Cech have been ever-present for the Gunners in the Premier League this season so their availability will be a huge boost for Arsene Wenger.
Monreal was forced off at half-time during last weekend’s 5-1 win over Everton at Emirates Stadium, but has recovered from illness.
The 31-year-old has missed training this week but is due to return to London Colney in time to face Mauricio Pochettino’s side.
Cech limped off during the second half against Everton after suffering a kick to his calf.
The club are said to be optimistic about his chances as reports suggest the injury is not thought to be serious.
Welbeck has been out with a hip problem since Arsenal’s 2-1 defeat at Bournemouth in January, but the England striker is making good progress and could re-join the first-team group this week.
Uwe Rosler was sacked by Fleetwood following a 3-0 reverse at Doncaster which condemned Town to a seventh straight defeat in all competitions.
Cambridge interim head coach Joe Dunne was pleased with how his side adapted to beat Grimsby 3-1.
Southend manager Chris Powell led the applause for Jason Demetriou after the right-back scored twice in the 3-1 win against Portsmouth at Roots Hall.
Morecambe boss Jim Bentley was the happier manager after Gregg Wylde's 90th-minute strike earned his side a point in their 1-1 draw with Forest Green.
Manager Gareth Ainsworth described Wycombe's 2-0 win at Cheltenham as a thoroughly professional performance.
Skipper Richard Wood scored the winner just before half time as in-form Rotherham pulled off a 1-0 victory at League One leaders Shrewsbury.