It was feared Keane would require an operation after he pulled out of the second leg of the Republic of Ireland’s World Cup play-off against Iran on Thursday.

Keane complained of stiffness in his right knee after playing the full 90 minutes of the Republic’s 2-0 win on Saturday.

He returned to United, where he has been having treatment, and after consulting his medical staff, Ferguson has decided against surgery.

The Reds manager is loathe to lose the influential midfielder at this critical time for United.

Ferguson feels he can patch Keane up again for Tuesday’s Champions League date with Bayern in the Olympic stadium in the opening game of the second phase.

‘‘He’s not had a scan and he isn’t having one,’’ he said. ‘‘We hope to get him back in training on Thursday and we hope he will be fit for Bayern Munich.’’

Keane’s return is welcome news for United after a miserable couple of weeks.

The champions have only managed one win in the six games Keane has missed since he damaged the patella ligaments in his right knee nearly four weeks ago.

However, despite Keane’s comeback he will only really dispel any lingering doubts about his knee when he has played a couple of matches without suffering any reaction.

That is the big test for the 30-year-old and he may yet need surgery on his knee before the year is out.

In a double boost for United, Ryan Giggs has recovered from his hamstring injury.

Giggs has reported no ill effects after making his comeback at Barnsley last night in Eric Winstanley’s testimonial.

Giggs, who has missed United’s last three games, played the first half of the match at Oakwell and was replaced by Bojan Djordjic at the interval.

The Welsh international is now clear to face Leicester at Old Trafford on Saturday and, more importantly, Bayern on Tuesday.